A brief history of Scheduling
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Dear Rafeal,
Here is a published article from 2005:
"
2005 AACE International Transactions
PS.08
Transparent CPM
Mr. Mark C. Sanders, PE CCE
If the direct output of a project schedule is too confusing for the stakeholders to understand, or if it takes too long to prepare informative output, then the schedule fails to communicate the health of the project in a timely manner. With the advancements that have been made during the last two decades in both CPM scheduling software and the computer hardware that runs these
applications, it is difficult to understand why the industry has not developed "enhanced" scheduling systems that can clearly, accurately, and quickly present the schedule data and critical paths to the stakeholders
"
With kind regards,
Samer
Samer,
“Construction operations are in reality, much more complex”
Yes this is correct, that is why we need more complex tools, and original CPM is too simple.
The fact that scheduling is at times done by inexperienced and incapable people are also true statements. But this is changing, now all Civil Engineering curricula includes some formal training in scheduling, all engineers I know, especially the young are versed on the use of CPM software.
Garbage-in garbage out is mostly due to the fact that the tool should be used by those who manage not by people foreign to the job. For the above reason this is changing not only here but in Russia as per Vladimir comments.
I would blame for the dark years Primavera, a company that bought good products to make a profit but never improved on them. They established themselves as the standard and our institutions followed their backward thinking doctrine of just to improve on the cosmetic side, they put on hold decades of improvements.
Best regards,
Rafael
Dear Rafael,
The article continue to say the truth, here is some more:
"
Insufficient Attention to the Integrity of Logic
Networks. The logic network is the heart of the
CPM method, but for various reasons it is often
relegated to a position of minor importance.
Formulation of good technique and rules to enable
training in network drawing has not occurred to a
sufficient extent. Therefore, schedulers who
could be described as good network analysts are
at a premium in the industry today. Consequently,
the phrase invented for computers "garbage in;
garbage out," is heard frequently in connection
with CPM schedules.
Most problems with networks stem from the fact
that, although they are often interpreted as
absolute mathematical models, engineering,
procurement, and construction operations are in
reality, much more complex than the networks
modeling,can handle with fidelity. The accurate
quantification of activities, deciding when one
ends and the next begins, and above all,
specification of the level of detail, are
constant problems in the preparation of networks.
"
Remember this is a 26 years old published article. Which means that it was reviewed by a panel of 3 at least and approved by them for publication.
With kind regards,
Samer
The article is wrong.
In any case CPM scheduling has been underdeveloped as a user-oriented tool and also as a science as both go hand by hand.
Functionalities that let you see the logic have been underdeveloped for long until now. These will turbo charge the status of CPM to the extent to make it manageable.
Open your eyes.
Best regards,
Rafael
Dear Rafael,
I moved up in time, but it still looks confusing to others as well. And it is published.
I am reading what others wanted to accomplish when they started the CPM and what we have now. That is why I am reading the 50s and 60s.
With kind regards,
Samer
Dear Rafael,
Read below what the introduction of published article in 1984 in AACE is saying:
"
1984 AACE Transactions
The CPM Technique in Construction: A critique, By Derek Mason
INTRODUCTION
The Critical Path Method (CPM) has now been in
use for a quarter of a century. As a technology,
it is young compared to, say, the science of pressure
vessel design, but its youth can no longer
be allowed to serve as an excuse for substandard
application. If the development of computers is
used as a comparison, the progress of CPM and
project scheduling looks somewhat anemic. So it
behooves us to take a critical look at the status
of the tool. Because of CPMs omnipresence in
the profession, the profession itself should also
be critically examined.
CPM scheduling has been overdeveloped as a
science and underdeveloped as a user-oriented
tool. It has all too often been forgotten that
schedules are not produced for schedulers, but
for managers. It is essential that service to
the user be given high operational priority.
"
With kind regards,
Samer
PS. Not sure whats inside the black boxes. I didnt open one for CPM before, sorry Rafael.
Samer,
CRITICAL PATH SCHEDULING - PHILOSOPHY AND EXPERIENCE
By Robert B. Vogeler, Meissner Engineers, Inc.
300 West Washington, Chicago 6, Illinois
Presentad At: The 6th Annual Convention
American Association of, Cost Engineers, June $7, 1962
Chicago, IllinOiS
THIS IS A 1962 PAPER ALMOST STILL IN THE ENIAC COMPUTER ERA.
Better get a couple of Cray machines.
http://www.deskeng.com/articles/aaathm.htm
Best regards,
Rafael
Samer,
For your knowledge original PERT computations were in error. Today no serious software uses their original mathematical assumptions and either use Monte Carlo or other modern mathematical methods to get a better estimate of the probability distribution. Because Monte Carlo is quite time consuming I prefer the other methods, and Monte Carlo as a tool to validate the other methods.
http://www.netmba.com/operations/project/pert/
See also
http://www.rand.org/pubs/research_memoranda/2008/RM3408.pdf
One of the paragraphs in the article you are referring reads as follows:
-"PERT and CPM scheduling techniques have many similarities. For example, each shows the relationships among activities and events, both include the project’s critical path, and the structure of each allows analysis of the tasks to be done, resources assigned to do them, and the time associated with each task. Both techniques use nodes to represent events (beginning and end of activities) and lines to represent the activities."
This really confused me as today many call PERT Diagram the Activity on Node representation and not the Activity on Arrow representation. This is kind of new to me, perhaps many software developers are wrongly using the PERT name or the article is wrong.
Maybe you can call PERT Distribution to their estimate of a Beta Distribution; this makes sense to me, but no more.
http://www.vosesoftware.com/ModelRiskHelp/index.htm#Distributions/Conti…
Best regards,
Rafael
Dear Vladimir,
You are going to love this:
"
CRITICAL PATH SCHEDULING - PHILOSOPHY AND EXPERIENCE
By Robert B. Vogeler, Meissner Engineers, Inc.
300 West Washington, Chicago 6, Illinois
Presentad At: The 6th Annual Convention
American Association of, Cost Engineers, June $7, 1962
Chicago, IllinOiS
Conclusions
I have not stressed the use of digital computers as a means of implementing Critical Path Scheduling. My reasoning in doing this is to stress the concept of a management science technique applied to construction, not a computer application. The concept of Critical Path
Scheduling has no direct relationship to computers and is only the sophistication of planning and scheduling (except where the number of activities is extensive, then computer use is required because of time and complexity). Therefore, Critical Path Scheduling should be examined
from its true perspective - a defined planning technique developed in our evolution of management science.
"
CPM true benefits (Saving time and cost) got lost during the development of "user friendly" sofisticated tools for trained experts.
With kind regards,
Samer
Dear Rafael and Vladimi,
I think that you will like reading this, it is a good reference:
NASA Scheduling Management Handbook
This handbook provides schedule management guidance for NASA Headquarters, NASA
http://spacese.spacegrant.org/uploads/Schedule/NASA_SMH_DRAF...
They have a very structured approach. Having the best people in the world automatically make everything easy. Not quite the same at Construction Sites.
With kind regards,
Samer
Dear Rafael,
The complete title of the paper is:
Scheduling 101: A "Behind-the-Scenes" Look at Basic Schedule Calculations
James L. Jenkins
Purdue University
West Lafayette, Indiana
Scott W. Kramer Joseph J. Orczyk
Auburn University Purdue University
Auburn, Alabama West Lafayette, Indiana
www.pmicos.org/topics/ aug2006tom.pdf
The link works. I tried it again now. Or you can google the paper.
With kind regards,
Samer
Hi,
This is interesting topic found in a guide: Common Time Robbers. This is actually written down in a guide. These guys know exactly what is wrong, but they have the discipline to make it work. Pretty much like what Vladimir is doing. The rest are not so lucky.
Scheduling Guide for Program Managers
www.dau.mil/pubs/gdbks/schedulinguide.pdf
APPENDIX B
Common Time Robbers1
• Procrastination
• Setting up appointments
• Too many meetings
• Monitoring delegated work
• Unclear roles/job descriptions
• Unnecessary crisis intervention
• Need to get involved in details to get job done
• Not enough proven or trustworthy managers
• Vague goals and objectives
• Too many people involved in minor decision making
• Lack of technical knowledge
• Lack of authorization to make judgment decisions
• Unreasonable time constraints
• Lack of commitment from higher authorities
• Too much travel
• Lack of adequate project management tools
• Poor functional communications/ writing skills
• Inability to relate to peers in a personal way
• Rush into decisions/beat the deadline
• Lack of reward (“a pat on the back can do wonders”)
• Expecting too much from one’s staff and oneself
• Going from crisis to crisis
• Conflicting directives
• Fire drills
• Lack of privacy
• Lack of challenge in job duties
• Bureaucratic roadblocks (“ego”)
• Empire-building line managers
• Too much work for one person to handle effectively
• Excessive paperwork
• Lack of clerical/administrative support
• Workload growing faster than capacity 78
• Dealing with unreliable subcontractors
• Personnel not willing to take risks
• Demand for short-term results
• Lack of long-range planning
• Being overdirected
• Overreacting management
• Poor lead time on projects
• Documentation (reports/red tape)
• Large number of projects
• Inadequate or inappropriate requirements
• Desire for perfection
• Lack of dedication by technical experts
• Lack of project organization
• Constant pressure
• Constant interruptions
• Project budget problems
• Shifting of functional personnel
• Lack of qualified manpower
With kind regards,
Samer
Samer,
Is this a continuation of the paper I referred under my posting #19 under this thread, is it Part 2?
“On the issue on continuous/discontinuous (non-split/split activities) the following article can serve as a start.”
http://www.pmicos.org/topics/aug2006tom.pdf
I could not get it following your link by pasting it.
Best regards,
Rafael
Hi all,
I found this article that describes the status of Scheduling in the Introduction and the Conclusion sections.
www.pmicos.org/topics/ aug2006tom.pdf
Scheduling 101: A "Behind-the-Scenes" Look at Basic Schedule ..
More of the same, but the good thing it is a published article by PMI college of Scheduling. Imagine that... they agree.
With kind regards,
Samer
P.S. You can only make toilet papers out of Contract Documents only after the elapse of 10 years period Rafael.
Dear Vladimir,
Thank you for your clear reply.
Regards,
SV
P.S. I agree that I need to experience other methods to understand the difference.
Vladimir and Safak,
My experience with prioritization with other software was that it was bypassed very frequently contrary to what happens in Spider Project, some might be skeptical about prioritization because of their prior experience. Phase Prioritization keep order on the house. I also would like to add that Spider have two levels of prioritization one at the Phase Level and another at the Activity Level, that in Spider you can have unlimited WBS and you can define a specific one for your phase prioritization while displaying the schedule on another WBS. Theoretically this can provide you with unlimited combinations as you can define unlimited WBS each with a single phase per activity, and then group the different phases using phase levels, kind of too much but the statistic is there for those who go overboard.
Resource leveling within Spider Project is a different experience, don’t judge it by your prior experiences with other software.
Best regards,
Rafael
Dear Safak,
At Caspian Pipeline Construction project we worked with the General Contractor and more precisely with the management company Starstroy specially created for CPC management.
We were involved in creating two schedules – one for the mobilization and another one – for construction.
Construction schedule was very detailed and this model was used for determining the technologies that will be used (four spreads, where the work will start, in what direction the construction will go at each part of the pipeline, etc.) and what quantities of machines and people are necessary to use to be on time.
The schedule that was created by the joint team of our consultants and our client was approved by the project management company that represented the Owner (Fleur) and then was used for tenders and contracting. Tender participants were required to agree with the schedule or to make necessary adjustments (there were none) and to demonstrate that they have sufficient amounts of necessary mechanisms and workforce (including certified welders).
The schedule had near 9000 activities with more than 1000 resource types.
The schedule was submitted to the management company and we were not involved in the following construction management.
Blue Stream schedule was developed for Gazprom with the similar purpose – to determine the durations and resources necessary for timely construction for future contracting.
We were and are involved in other pipeline construction projects and not only at the planning phase as in these examples but also at the execution stage. These two projects are not typical for our activities.
I do not believe in manual leveling. When there are thousands resource types it is impossible. Playing what if shall be manual because only people know if it is possible to add some resources to some crews. But if the crews are known the software shall provide the results of your what if evaluations.
If you created the manual schedule then you will need to do manual scheduling again when the information will change and it is changing each time when you enter actual. It is impossible. If you start to use automatic leveling then your initial manual schedule will not work and the baseline order of work may be rejected.
In Spider Project we have special function (Previous version support) that can help to keep the order of work that you prefer but I did not see this functionality in any other software. I think that it is necessary to rely on automatic leveling that takes into account user defined priorities but tries to minimize overall project duration. Playing with priorities shall be manual, not the leveling itself. In large projects it is very time consuming.
On the slide 37 of this presentation:
http://www.spiderproject.ru/library/eng/Spider%20Project%20Presentation…
you may find the Linear Diagram (Time-Location Chart) of Caspian Pipeline Construction Project. I don’t remember special publications on this topic.
Best Regards,
Vladimir
Samer,
If you do not use the schedule as a dynamic tool, even if “drawn” by an “expert” scheduler it is just toilet tissue paper. The schedule is dynamic; therefore the management team must be able to use it on demand.
The action scheduler will use the tool to determine course of action using “what-if” scenarios. The CPM will not be a substitute to the skills of the manager, this is an erroneous belief. The CPM will assist the team to analyze different scenarios, if the model is good and maintained as a dynamic thing to represent changed conditions it will provide good assistance.
Most probably the scheduler will look at the two infamous indicators of what is driving the schedule at the moment of the analysis; these are total float and free float, named in order of relevance, the first with very dominant priority. If your software provides you with true float after resource leveling you are a step ahead, if you know all driving links even better, beware that resource dependencies usually are kind of concurrent and the delay of only one can release all others.
Of course other scenarios such as changing work logic or changing the means and methods should be considered.
What-if is the key, if not performed frequently you are not managing the schedule with the assistance of the CPM, you are forcing the CPM to follow you, you are using it just as a record keeping tool. What-if is not easy because every time you change the scenario the Critical Path, the driving relationships and demand of resources vary.
Because I am an action scheduler when our schedules start to fall behind we do a lot of what-if analysis and this way we keep the jobs on course. Because is not easy and can be time consuming is why I am so concerned about the understanding of what is driving my schedule. At any given time I am concerned about all activities that cannot be delayed to avoid delaying total project duration and also to avoid delaying some non critical but immediate successors, these are non critical drivers. Any tool that assists us to understand the logic is welcomed.
I would like to add that if when resources loading you get into too much granularity this will make you lose perspective as the resource dependencies will exponentially increase. Construction jobs are managed at the crew level; use this as your unit or at least keep them in teams.
Best regards,
Rafael
Dear Vladimir,
I have question out of topic:
For "Caspian Pipeline Construction" and "Blue Stream" Pipeline" projects, did you act as an advisory subcontractor to "GASPROM"?
If so; what are the ideas or comments on the projects by "General Electric, Bechtel, Royal Dutch Shell, BP, SOCAR, TPAO,...." (who shall be involved?) through your looking glass for the project?
I can understand that you are responsible about confidentiality to your customers but can you could provide us some demonstrations or papers about this kind of projects?
For the discussion: I prefer and trying to implement; manual resource levelling for the baselines(I think achievable and important) and using software resource levelling for periodical updates and forecasts.
Regards,
Safak VURAL
Dear Samer,
CPM is the method of the project scheduling that ignores resource, supply and financial restrictions.
I think that you mean proper project scheduling that takes into account all existing constraints.
And your phrase about perfect management process I understand as the proposal to discuss the benefits of proper projectt management that includes project planning and scheduling.
When I write about creating project schedule model I mean the model that will answer any what if question. It means that managers can estimate future results of potential actions before making the decision.
Good Project resource constrained schedule helps to optimize the workforce and machines, to minimize the waste of the working time and project duration, to optimize the supply schedule.
Risk management is another source of potential benefits.
And since nothing goes as planned an ability to reschedule the project and reassign resources optimally in the real time is also a large benefit.
If you create shorter schedules, use less resources to achieve the same goals, always have all required information for communications and decision making, have sufficient contingency reserves for risk events that were calculated and optimized (not too small. not too large), etc. you will save a lot of money and a lot of time.
But I repeat that if somebody somewhere drawed CPM schedule that is not used for the real management and decision making then it is a waste of time.
Best Regards,
Vladimir
Dear Vladimir,
Theoretically, let us assume the managment process is perfected. Lets assume that 50% of the projects worldwide are run effectively and efficiently to the best of everyones knowledge (I would like to know your estimate). We come back to the original question:
How is the CPM helping the decision makers in the time and cost issues? Which is the original goal of a CPM.
I know that if you are on the project with your CPM tool, things are likely to be under control and it will benefit the project. But that is an "ad hoc" solution.
With kind regards,
Samer
Dear Samer,
if project management does not use created schedules then they are useless.
Construction manager shall be involved in the schedule development and will require from supervisors to follow the planned order of activities execution. The schedule defines how many people shall work at any site area at any type of job. Out of sequence execution means penalties to supervisor.
Crews get their work plans directly from the scheduling software and these plan shall include planned physical amounts of work to be done.
Reports go to the scheduling program and the schedule is recalculated. The work plans for the next shift (day) are published.
It is usual to have computer (notebook) on site. And it is usual to have phones on site. So it is not hard to connect to the Central office, to submit the reports and to get the revised plan if you dont want to train supervisors.
Another option that we use here on some projects - the supervisor comes to work 20-30 minutes earlier, switch on the computer, updates the schedule and prints work plans for construction crews.
At the end of the shift crew leaders fill (on paper) the fields against each planned activity with actual quantities that were done by their crews. These reports are submitted to the supervisor who may accept or rejext them but his acceptance means quantities confirmation.
The supervisor enters actual data in the notebook and send to the office or in the scheduling program creating new updated project version.
Information from the construction site, from supplies department, from financial department is merged in the PMO.
Reports to the owner are made by PMO and we suggest to show project trends, the best - success probability trends if risk simulation was approved. 100 pages report will not be read.
In any case - if the schedule lives by itself without guiding production force it is useless.
Dear Vladimir,
The CPM was created at a Business oriented company to serve a certain need. It was later determined that this tool did not work by the same company, and the founders had to leave and open their own practices. It was further devleped at research institutes and huge organizations.
It is very obvious that the origin of CPM did not start with the end customer in mind. It is a systematic approach managed by specialist. What we have in the market are intelligent tools that needs "Certified" people to run it.
What I am talking about is something different. Construction Projects are initiated by Owners, Managed by Project/ Construction Managers and executed by supervisors. These three categories do not have tools to reduce the project time and cost within their immediate reach except a calculator and to the extent that any of them is computer literate.
What are the avilable solutions to the time and cost decision making saving beside using their experience: Owners drink and smoke to relax their nervous systems, PM/CM look at the skies to receive wireless clues and supervisors have calculator and drawings in their hands running around to complete the job as efficiently as possible and if the PM/CM is smart, then it will effective as well.
What do you expect of an Owner/PM/CM if you give him a monthly report of 100 Page CPM with pictures and cummulative graphs, etc. How do you expect them to take the right time and cost savings. Especially since every single day at site labor cost, is more expensive than the tool.
The more important question is that how do you expect people who are hired on a monthly basis by the Owner to provide him with solutions to complete the job faster. It is not possible logically because it is not covered contractually in most cases, and it means that your are asking people to reduce their income.
If you can explain to me logically how your average Owner who does not know anything about CPM can save time and cost by using the available CPM tools in the market, I would very much appreciate that. They are the entity most interested in time and cost, and they cant use the tool. And I am very confident that they know everything about money and interests.
The current tools, to my knowledge, are managed by specialist, and are good for progress monitoring. You can have a indication about what MIGHT be happening at site depending on how good the model it.
We are talking about a different tool. That is why the oldest schedule in history marked on a bone, can be a good start. If it was easy to be understood by a 35,000BC person, any living person now can use it.
With kind regards,
Samer
We dont advise our customers to use external services.
If construction managers did not take part in the schedule development the schedule is good for wall paper.
The contractor schedule shall advise site managers what works shall be done in the next shift, procurement managers shall have the information when and what amount of materials will be required, etc.
Contractor project schedule shall supply project participants with the information that is required for his/her tasks. It shall be updated frequently and deal with physical work volumes, real costs, real resources.
It shall be created inside the organization and shall be based on the internal corporate norms and technologies.
It is necessary to train contractor managers because schedule development lasts until the project finish.
The practice that you described (hiring external scheduler) is not common in the countries where we work. And the task of PM System implementation is to teach our customers to manage their projects without external help.
Best Regards,
Vladimir
Dear Vladimir,
This is very interesting information. I think that if you can make a presentation and put it on spider website, it would be useful for many.
The issue of training a staff from zero, building a database and make them productive seems ideal. But I will take your word. It can happen, but that is not usually the case.
What you are describing is a project management solution with providing services to the Contractor. Chances are that you Schedulers are building the Model for the Contractors. That is why it is working. In most cases, the Contractor buys the software, and hires a scheduler to do the job.
It seems to me that the solution is in running the black box correctly. We are talking about creating an Interface between the site and the black boxes. This consist of prefessional service companies that can run the software and understand construction at the same time. This is a partial solution because the information at site changes by the minute. And when you have 50 people working 1 or 2 shifts, things really change daily. In addition, the majority of the users will not allow a 3rd party to have any part of their data!
With kind regards,
Samer
Dear Samer,
Spider Project is used by the companies that manage $100000 projects (flats repairs and similar projects) and companies that manage $30bln programs like preparation of Olympic Games (arenas, hotels, railroads, sea ports. airport, utilities, power plant, etc.). I don’t agree that there is some mimimal budget when it is useful. My experience shows that it is always useful.
This company that repairs flats is even more happy because they saw immediate benefits having full information on required materials, resource schedule, cost forecasts, etc.
And the benefits are much larger than 2% of the project budget. They paid $10000 for the software, training and consulting and returned their money immediately - their customers were happy to pay more money for fast, reliable and clean project management when they know the exact days when the work will be done and can track the progress. They also saved money buying necessary materials in necessary quantities at required time.
Our other client built the high-rise building using just in time technology. They called to our office and informed us that the construction was finished at the exact day that was planned one year earlier and we congratulated them. This building was built in the city center and without the precise resource scheduling they may have a lot of problems.
This setup job is necessary, takes time and requires dedicated team. But this job is needed in any case - there is a need in the corporate standards and norms if the company wants to manage its resources and costs. I cannot imagine corporate project management system without corporate standards for production rates, cost and material estimates, etc.
But if these standards are established project scheduling became easy and reliable.
We spent more than 3 months creating norms and resource databases, typical fragments and WBS templates for Caspian Pipeline Construction Project.
After this was done it took three days to create the detailed schedule model, to make all necessary what if calculations, to determine what resources are needed at any point in time, etc.
Our analysis showed that without this model we would be late at the rice fields and the project could be at least half of the year late.
Our next project was Blue Stream pipeline and everything was ready in two weeks because we already had necessary databases and fragments.
And I want to add that I am mathematician but was and am involved in planning and management of many construction and other projects. Creating useful PM software it is necessary to have site experience. When we implement PM System and Spider Project in new company we manage pilot project together sharing with our customers our practical experience. And it includes not only software implementation but also project management procedures and decision making, staff motivation, communications, etc. The software is a part of the project management system and does not work by itself.
We estimate the benefits of proper planning and management in at least 10% of the project budget. And if PM system implementation will cost less then the company will get its money back on the first project. And usually it happens this way.
But I mean the implementation of the project management system and resource scheduling that is based on real data. Drawing schedules does not save much money.
Best Regards,
Vladimir
Dear Vladimir,
We are talking about the same thing from different angles. You are the mathematician and I am the site person.
I am sure that in order to complete the requirements in your 1st paragraph, you need a capable system administrator to do the job with a great setup. It would be interesting to find out how many sites on earth have these capacilities. My guess that you need a project between $15-50Million, to start thinking about this setup. Roughly speaking you will need to spend 1-2% of the project value to start speaking this language.
Now this is the important question. A Program is a normal requirement on the project, from your experience, paying the 2% are you getting your ROI or are you wasting money and getting in trouble because of bad models.
With kind regards,
Samer
Dear Rafael,
I did not think that the guys in the 60s messed up. They had 3000 projects running at the same time and they wanted to land on the moon. So I think that it is safe to say that if you want to build a project on earth for $5M or less, you do not need a progam. You need a calculator only. On the other hand, if you want to go outside the Earth, they you need computers for communication back and forth. I think that construction (like LEGO) is done manually up their as well.
On the other hand, if you have layers and layers of people all over the place, and you are paying them. Then chances are if you buy the black box, and create a model, some kind of calculations is better than nothing. A little order is good. And maybe, just maybe, if you hire the best guys to create the model and maintain the system, then you can get COST AND TIME savings.
With kind regards,
Samer
Dear Rafael,
I did not think that the guys in the 60s messed up. They had 3000 projects running at the same time and they wanted to land on the moon. So I think that it is safe to say that if you want to build a project on earth for $5M or less, you do not need a progam. You need a calculator only. On the other hand, if you want to go outside the Earth, they you need computers for communication back and forth. I think that construction (like LEGO) is done manually up their as well.
On the other hand, if you have layers and layers of people all over the place, and you are paying them. Then chances are if you buy the black box, and create a model, some kind of calculations is better than nothing. A little order is good. And maybe, just maybe, if you hire the best guys to create the model and maintain the system, then you can get COST AND TIME savings.
With kind regards,
Samer
Dear Samer,
First of all, let me tell that I agree with you.
More than that I am strongly against project schedulers that draw the schedules.
When implementing PM System we suggest to create a set of databases (reference-books) including, Resource Dictionary, Material Dictionary, Cost Components Dictionary, Material Requirements per unit of volume for typical activities and assignments, unit costs for typical activities and assignments, Typical Resource Crews, Resource Productivities for typical assignments, etc.
The usage of these databases is mandatory.
Besides, PMO creates a set of typical fragments - small projects that model typical technologies (like construction of 1km of the pipeline, making 30m2 wall, etc.). These fragments are created with the use of above databases.
Creating new project model is very simple. It is enough to create WBS or use the template and then use Replace the phase by the new project function selecting requirent fragment and adjusting the volumes of work.
With the corporate reference-books and libraries it is easy to create new project models, these models are more reliable (are based on the corporate norms), everybody understands what data are in the foundation. This is the right way to create schedule models.
Dear Vladimir,
Please read the opinions of other as well on the same issue. Amazingly it is the same:
pscinc.homestead.com/CPM.html
With kind regards,
Samer
Samer,
The paper is related to a complaint about the status quo of PDM software at that time, yes they were correct. At that time and for decades software developers did nothing practical to the resolution of this problem same as Primavera who limited to buy P3 from another developer, then SureTrak also from another developer, then P3e also from another developer that eventually came P6 because of the many bugs and finally to end up being acquired by Oracle. Other software developers are in the same boat, adding nothing relevant but cosmetic.
Yes PDM is more complex than the CPM of the 60’s because it expands the modeling possibilities, probably it was too much for these developers that never introduced much needed functionalities to understand it. Unbelievable, but initially CPM did not take into considerations for limited resources. Take for example resource float, without float you only got a Bar Chart, after resource constraining how can you understand your CPM without true resource float? How can your contract talk about float if the required software is incapable of providing you with the true value of this metric?
About the complaint on how some other functionalities such as constraints that mess with accepted CPM computations I agree, if the software developer insist on these being available then just avoid them in your modeling. Unfortunately these developers never provided for this metrics to be available for comparison purposes without an easy way to toggle them on and off forcing some of us as well as many analysts to either remove them temporarily or keep a second model without the constraints that fool the PDM backward computations. This is an issue when it is the Owner who requires you to include such implementation of constraints.
As far as I recall in this paper there was also the issue about the technical competence of those doing CPM scheduling, this is not for everyone, the scheduler must be knowledgeable of what is being modeled and must be capable to deal with the available software at the time. Don’t blame the tool for its irresponsible use, start requiring that the persons in charge of the creation of the model be capable and competent; this includes the scheduler as well as the project manager, if the project manager is incapable of dealing with CPM at least require for a capable assistant.
Spider Project team is making all attempts to make it possible for you to understand the logic, they provided us with true resource float and are moving forward with other functionalities with this purpose, issues other developers don’t dare to explore. The concepts are not difficult to understand, the programming is, we should encourage the developer to tame the software for us. Spider team is raising the bar and this will eventually make others to follow for the benefit of all, in a way PP is part of this, we represent the end user, wise developers are listening.
Best regards,
Rafael
Dear Vladimir,
First of all, let me tell you that I hope that I have the opportunity to work on your software in the future.
The primary issue that I have is that a tool must serve the Owner/ Construction Manager in taking the right decision on the project to save time and cost. I also believe that this is much needed at any point in history.
I can safely say that according to my experience a project of a budget of around ($5 Million, 2 years) can be completed with without anytools whatsoever. The only scheduling that is needed is an excel sheet and a calculator. The Construction Manager can draw the schedule with excel on ONE page and monitor it and reduce the cost on a daily basis. I have done this at least 50 times.
On larger projects, where the uncertainities are more, different people are working on different tasks, the issue becomes harder. The actual plan is difficult to FORM. Time is needed to create it, and many other factors come into play. For the sake of argument let us assume that the only issue here is to come up with a plan to save time and money. Speaking from my experience, I get 5000 activites (150 pages) projects frequently, and I review and return them within 4 hours for the simple reason that it is not representing the project. Most frequently, a planner prepares the Schedule, and the experienced people do not have the time to check the Method Statement, Constructabilities, Deliverables, relationships, and Contractural constraints.
I am confident that you program Spider is a magnificent tool. The issue in not with the black box. The issue is with creating the model. The Construction Manager/ Owner (who are the decision makers) must be able to communicate directly with the software to take the important decision. Nowadays, the tools are driven by Schedulers who know how to use the tool (to some extent/ depending on their experience) without the proper interaction from management. This tool is used to create Schedules to show contactual milestones, and unless the other party is experienced enough to debug the submitted program, it become a contractural document that is supposed to be monitored and tracked to achieve the project.
My suggestion is simple, Model Creation must be simple enough like punching the buttons on a calculator. I think that you need to communicate with Texas Instrument and create such a tool.
I also suggest that you send the 4 guys copies of Spider with all the supporting documents. Let them test it and use it and next they sit down and have coffee, they would be able to talk about something of value available on the market and ENR can publish the state of the available tools around the world. Of course, I understand that there are many other issues at play here, but it seems that they guys genuinely want to improve the status.
No body is talking about the Black Box, everyone is assuming it is working correctly. The issue here is that getting the right information, in the right order to create the right model is something left for specialist.
With kind regards,
Samer
Dear Vladimir,
First of all, let me tell you that I hope that I have the opportunity to work on your software in the future.
The primary issue that I have is that a tool must serve the Owner/ Construction Manager in taking the right decision on the project to save time and cost. I also believe that this is much needed at any point in history.
I can safely say that according to my experience a project of a budget of around ($5 Million, 2 years) can be completed with without anytools whatsoever. The only scheduling that is needed is an excel sheet and a calculator. The Construction Manager can draw the schedule with excel on ONE page and monitor it and reduce the cost on a daily basis. I have done this at least 50 times.
On larger projects, where the uncertainities are more, different people are working on different tasks, the issue becomes harder. The actual plan is difficult to FORM. Time is needed to create it, and many other factors come into play. For the sake of argument let us assume that the only issue here is to come up with a plan to save time and money. Speaking from my experience, I get 5000 activites (150 pages) projects frequently, and I review and return them within 4 hours for the simple reason that it is not representing the project. Most frequently, a planner prepares the Schedule, and the experienced people do not have the time to check the Method Statement, Constructabilities, Deliverables, relationships, and Contractural constraints.
I am confident that you program Spider is a magnificent tool. The issue in not with the black box. The issue is with creating the model. The Construction Manager/ Owner (who are the decision makers) must be able to communicate directly with the software to take the important decision. Nowadays, the tools are driven by Schedulers who know how to use the tool (to some extent/ depending on their experience) without the proper interaction from management. This tool is used to create Schedules to show contactual milestones, and unless the other party is experienced enough to debug the submitted program, it become a contractural document that is supposed to be monitored and tracked to achieve the project.
My suggestion is simple, Model Creation must be simple enough like punching the buttons on a calculator. I think that you need to communicate with Texas Instrument and create such a tool.
I also suggest that you send the 4 guys copies of Spider with all the supporting documents. Let them test it and use it and next they sit down and have coffee, they would be able to talk about something of value available on the market and ENR can publish the state of the available tools around the world. Of course, I understand that there are many other issues at play here, but it seems that they guys genuinely want to improve the status.
No body is talking about the Black Box, everyone is assuming it is working correctly. The issue here is that getting the right information, in the right order to create the right model is something left for specialist.
With kind regards,
Samer
Hi Samer,
what is your proposal?
Remember track "Let’s Challenge Spider"?
Ask or suggest something that is required but is not supported.
Spider Project is a tool for finding proper management decisions based on the information that was entered. If you created reliable schedule model then the software shall provide you with the optimal or near optimal solutions for the project schedule, resource assignments and usage, that take into consideration all existing constraints.
What is missing?
The paper that you mentioned described the oppinions of some people. By the way none of them knew Spider Project. Do you agree with them?
Best Regards,
Vladimir
Dear Rafael,
I came accross a very interesting article published in the ENR magazine in 2003:
" Critics Cant Find the Logic in Many of Todays CPM Schedules." It is a 4 page article quoting "Priests" and "tool makers" in this field.
www.cpmguru.com/.../ENR%20-%20Critics%20of%20Todays%20CPM%20Schedules.p…
So, we can reasonable say that up to 2003, according to published sources, that the state of Scheduling is a mess.
The basic need of the Owner/Construction Manager to save time and money is not met "easily" by the available tools in the market. The user-tool interface is a mess. Users cant transform their ideas into CORRECT networks of logic easily, in order for the black box to calculate it correctly.
I still think that we need to get the guys in a brainstorming session and transform that "Lebombo bone" into a modern tool. Think of it like an ipod. On one side you input the data and on the other side you get the time and cost savings.
I think that I just came up with the next ORACLE market penetration idea :) load your software of choice on ur ipod for $9.99/mo :)
With kind regards,
Samer
Dear Mike,
Yes the Slide Rule is very important discovery. It lasted 300+ years.
But I still think the newest information is the "Lebombo bone" from 35,000B.C.
With kind regards,
SAmer
Hi Samer
I forgot the most important one.
Circa 1650 the invention of the slide rule following John Napiers discovey of logarithms.
Best regards
Mike Testro
Dear Mike,
hahah. Thank you for the remark. I will do better next time.
With kind regards,
Samer
Hi Samer
A excellent piece of research but you missed out some English contributions:
1. Charles Babbage - Difference Engine - 1849 - a fully programmable calculating machine.
2. Bletchly Park WW11 code breaking computer constructed by Alan Turin circa 1941
3. Clive Sinclair first pocket calculator using LEDs early 1960s
And it was the Ancient Greeks who discovered electricity by rubbing an amber rod with silk to generate powerful static charges - the Greek word for amber is electron.
Best regards
Mike Testro
Dear Rafael,
The base 21 idea gave me a good laugh. Thank you.
With the help of google and few ideas looking at a schedule in front of me, I decided to find out the history of paper, mathematics, electricity, computing tools, CPM, and here are the findings:
Paper:
1. Early people discovered that they could make simple drawings on the walls of caves, which was a great place for recording thoughts, but wasnt portable.
2. About 5,000 years ago, Egyptians created "sheets" of papyrus by harvesting, peeling and slicing the plant into strips
3. 3,000 years. The person credited with inventing paper is a Chinese man named Tsai Lun.
4. 10th century, Arabians were substituting linen fibers for wood and bamboo, creating a finer sheet of paper
5. In 1448, Johannes Gutenberg, a German, was credited with inventing the printing press
Tools
1. The original compact calculator was the abacus, developed in China in the ninth century.
2. The young French mathematician Blaise Pascal (1623-1662) invented the first adding machine in 1642, a clever device driven by gears and capable of performing mechanical addition and subtraction.
3. The first commercially successful adding machine was developed in 1886 by William Seward Burroughs (1855-1898).
4. The "Millionaire," a machine invented by Otto Steiger in 1894, was the first adding machine also capable of direct multiplication.
5. The Atanasoff–Berry Computer (ABC) was the first electronic digital computing device.[1] Conceived in 1937, the machine was not programmable, being designed only to solve systems of linear equations.
6. The hand-held pocket calculator was invented at Texas Instruments, Incorporated (TI) in 1966 by a development team which included Jerry D. Merryman, James H. Van Tassel and Jack St. Clair Kilby
The numbers:
1. The Arabic numerals or Hindu numerals or Hindu-Arabic numerals are the ten digits (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). The decimal Hindu-Arabic numeral system was invented in India around 500 AD.
2. While the word algebra comes from the Arabic language (al-jabr, الجبر literally, restoration) and much of its methods from Arabic/Islamic mathematics, its roots can be traced to earlier traditions, most notably ancient Indian mathematics
2. Prehistoric mathematics: The origins of mathematical thought lie in the concepts of number, magnitude, and form.[8] Modern studies of animal cognition have shown that these concepts are not unique to humans. Such concepts would have been part of everyday life in hunter-gatherer societies. That the concept of number evolved gradually over time is evident in that some languages today preserve the distinction between "one", "two", and "many", but not of numbers larger than two.[8]
The oldest known mathematical object is the Lebombo bone, discovered in the Lebombo mountains of Swaziland and dated to approximately 35,000 BC.[9] It consists of 29 distinct notches deliberately cut into a baboons fibula.[10] There is evidence that women used counting to keep track of their menstrual cycles; 28 to 30 scratches on bone or stone, followed by a distinctive marker.[11] Also prehistoric artifacts discovered in Africa and France, dated between 35,000 and 20,000 years old,[12] suggest early attempts to quantify time.[13]
The Ishango bone, found near the headwaters of the Nile river (northeastern Congo), may be as much as 20,000 years old and consists of a series of tally marks carved in three columns running the length of the bone. Common interpretations are that the Ishango bone shows either the earliest known demonstration of sequences of prime numbers[10] or a six month lunar calendar.[14] Predynastic Egyptians of the 5th millennium BC pictorially represented geometric designs. It has been claimed that megalithic monuments in England and Scotland, dating from the 3rd millennium BC, incorporate geometric ideas such as circles, ellipses, and Pythagorean triples in their design.[15]
4. The most ancient mathematical texts available are Plimpton 322 (Babylonian mathematics c. 1900 BC),[1] the Rhind Mathematical Papyrus (Egyptian mathematics c. 2000-1800 BC)[2] and the Moscow Mathematical Papyrus (Egyptian mathematics c. 1890 BC). All of these texts concern the so-called Pythagorean theorem, which seems to be the most ancient and widespread mathematical development after basic arithmetic and geometry.
Electricity
1. Benjamin Franklin and Electricity In June of 1752, he performed his famous kite experiment, drawing down electricity from the clouds and charging a Leyden jar from the key at the end of the string.
2. Thomas Edisons greatest challenge was the development of a practical incandescent, electric light. Contrary to popular belief, he didnt "invent" the lightbulb, but rather he improved upon a 50-year-old idea. In 1879, using lower current electricity, a small carbonized filament, and an improved vacuum inside the globe, he was able to produce a reliable, long-lasting source of light.
CPM
CPM was the discovery of M.R.Walker of E.I.Du Pont de Nemours & Co. and J.E.Kelly of Remington Rand, circa 1957. The computation was designed for the UNIVAC-I computer. The first test was made in 1958, when CPM was applied to the construction of a new chemical plant. In March 1959, the method was applied to a maintenance shut-down at the Du Pont works in Louisville, Kentucky. Unproductive time was reduced from 125 to 93 hours
Now we are using all of the above to save time and money on our construction projects. Now I have to say that my favorite was discovering tha the oldest known mathematical object is the "Lebombo bone".
With kind regards,
Samer
Hi All
The standard abacus is a marvelous calculating machine - I never mastered it although I tried.
I once worked with a Japanese company in Baghdad and the Project manager did all his calculations on an abacus.
The European engineers were intrigued because thay used somewhat rudimentary calculators from Texas Instruments. (this was in the late 80’s pre computers)
I set up a challenge of abacus v calculator with a somewhat complex calculation - something like:
((197*42)/18)+(14.57*28.6)=??
The abacus won by a fair margin to 2 decimal places - 876.37.
Best regards
Mike Testro
Samer,
About the Abacus thanks for highliting about the decimal point is amazing. And they only used base 20, imagine if using base 21 (boys edition abacus).
Best regards,
Rafael
Dear Rafael,
Thank you for your kind reply. I think that the softwares that we have nowadays are doing a great job at solving problems. And I hope that their black boxes are programmed correctly.
I saw that you referred to the abacus earlier and that it is not designed to solve the decimal points. So I started a small google search and found the following the you might find interesting about the accuracy of "human" before the word computer came to existance:
http://en.wikipedia.org/wiki/Abacus
" Native American abaci
.....
Altogether, there are 13 rows with 7 beads in each one, which makes up 91 beads in each Nepohualtzintzin. This is a basic number to understand the close relation conceived between the exact accounts and the natural phenomena. This is so that one Nepohualtzintzin (91) represents the number of days that a season of the year lasts, two Nepohualtzitzin (182) is the number of days of the corns cycle, from its sowing to its harvest, three Nepohualtzintzin (273) is the number of days of a babys gestation, and four Nepohualtzintzin (364) complete a cycle and approximate a year (1 1/4 days short). It is worth to mention that in the Nepohualtzintzin, amounts in the rank from 10 to the 18 can be calculated, with floating point, which allows calculating stellar as well as infinitesimal amounts with absolute precision."
Now this is the first time that I read that article, but I found it interesting that they are using "floating" and "absolute precision" for a systm that was invented by humans 4000 years ago.
If you dig a little deeper and click on the Mayan culture and CONSTRUCTION, you will find the following:
"The Classic period (c. 250–900 AD) witnessed the peak of large-scale construction and urbanism, the recording of monumental inscriptions, and a period of significant intellectual and artistic development, particularly in the southern lowland regions.[9] They developed an agriculturally intensive, city-centered empire consisting of numerous independent city-states. This includes the well-known cities of Tikal, Palenque, Copán and Calakmul, but also the lesser known Dos Pilas, Uaxactun, Altun Ha, and Bonampak, among others. The Early Classic settlement distribution in the northern Maya lowlands is not as clearly known as the southern zone, but does include a number of population centers, such as Oxkintok, Chunchucmil, and the early occupation of Uxmal."
You will agree with me that these guys 4000 years ago, planned well and scheduled their Construction sites well. They had limited resources and were able to build structures with local materials that lasted until our present day.
With kind regards,
Samer
Samer,
I tried to illustrate the issue on how wrong and misleading many software are by not being able to get it right within a simple two activities schedule, I don’t believe a computer is necessary to understand the five activities schedule either. Is not a black box, is an easy to verify fact.
That different software can yield different results and maybe only one can provides you with true float after resource leveling is no reason to throw to the floor these tools, they can still be of some use.
Do not throw to the floor your CPM software as if no longer wanted toys, even if not high end, even if used as a low end calculator or an abacus.
Best regards,
Rafael
Dear Mike,
Many thanks for your kind support. I highly appreciate it.
I think that you should have entered this discussion a while back, but it is not too late.
Dear All,
For me a Scheduling Programs are a big calculator. Everyone can use the +, -, *, /, = and punch in the numbers and get the right answer. Unfortunately, not everyone can juggle few thousand activities using windows and then VERIFY the right answer.
The level of mathematics envolved in programming the box is high, and an engineer (Junior or Senior) does not have the time to understand it (even if can understand it, his company is not paying him to understand it), bearing in mind that, it has to be understoond and verified by the other party. So, it is better to assume that the black box is giving the right answers until it is critical enough project to veryify the results using another black box.
History speaks for itself. Civilizations were built without computer or programs. CPM came in the 1950s. Needless to say, that current civilizations underwent TWO world wars without computers or programs.
I can very much assure you ALL, that Engineers CAN build construction projects successfully without ANY computers or ANY Schedules. If the Romans, Egyptians, and Chinese succeeded in building Empires for hundreds and thousands of years, then my statement is valid. Can you tell me the name of the software that enabled the British Empire (largest Empire in history) to rule for hundreds of years! The answer is No. You agree with me that it required a lot of planning and scheduling. That is why, I am confident that todays Engineers can do the same thing if they are put under similar circumistances, for the simple reason that they have more education and more understanding of Engineering than the "Engineers without Degrees" hundreds of years ago.
Let me state very clearly that the CORE purpose of a CPM software is to SAVE TIME AND MONEY. If the softwares that engineers are using these days are not providing this, then the original purpose is lost. These tools are adding more confusion and are not being used properly. Gates was successful in creating a "friendly window environment" that other are using as "input" to the black box, and "output" to view the results. Scheduling Software are like tools in the hands of users. Can a T-square draw a perfect drawing! You are mistaken to think it can. Even if it has a buzzing name.
Ultimately, scheduling tools must evolve in order to enable the user with "reasonable" experience to use the tool to save him/her time and money, and for this result to be verifed (i.e, a checking mechanism).
With kind regards,
Samer
Hi Mike,
we live in a free world and everybody can do what he/she likes if it does not harm anybody.
I can imagine that in your projects resources are unlimited, Unfortunately in most projects where we are involved there are resource restrictions and creating project schedules we cannot ignore them. Our schedules consist of many thousands activities and manual levelling I consider as a joke.
Most people just draw their schedules and their schedules do not answer to what if questions. They are almost useless. When people manage projects they manage resources and if the model does not answer to the questions on resources it does not help much.
Best Regards,
Vladimir
Hi Samer
I have had the same knockabout chat with these two eggheads on the topic of resource levelling on a number of occasions on PP.
I am with you Samer - I dont trust any computer to make my decisions - especially when it wont tell me what it has done to my schedule.
I now let Raf & Vlad speak to each other on their own level where they can do least harm to the rest of us.
Best regards
Mike Testro.
Dear Rafael and Vladimir,
I agree that the Schedule is very important for the "what if" analysis, and it is used for many decision making actions pertaining to recourses. Actually, this can not be done in a timely manner without these tools.
I am very much against trusting the black box without understanding its formula. The problem is that people start applying the constraints and lead and lags, calenders and local and global options without understanding the black box formula. They you have an output that is support to predict the time and cost throughout the next couple of years.
Unless you have a systematic process to verify the input, and make sure that you Model is correct, there is no way to make certain that the output is correct unless you rely on experienced engineers with prior experience in a similar project.
With kind regards,
Samer
Dear Samer,
if resources are limited, if there are financial restrictions, if logistics set restrictions on supplies and the schedule does not take this into account the schedule will be unrealistic.
The purpose of creating schedule model is to get help with decision making. If project manager can get the answers to the questions like what if we will use additional resources, what if we will get the loan, etc. using computer model then it is worth the efforts for its creation.
Resources are always limited. The client may ignore this but not the contractor.
Best Regards,
Vladimir