Modern Schedule Compression techniques

WHAT IS THE PURPOSE OF PROJECT CRASHING ANLYSIS? 

The project manager is confronted with having to reduce the scheduled completion time of a project to meet a deadline. Project duration can often be reduced by assigning more labor to project activities, in the form of over time, and by assigning more resources, such as material, equipment, etc. However, the additional labor and resources increase the project cost. So, the decision to reduce the project duration must based on an analysis of the trade-off between time and cost.

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That husky dog was a good one



haaa haaa haaaaa haaaaaaa



Gud berak after all those heated crap in other threads

Hi Ravira



I relate more to the seagull management type.



They arrive in large flocks - squark a lot - crap all over the place - eat all the food and then fly off.



While on the subject of management systems - has anyone worked under the Husky Dog manager management system.



This one is where:



Only the dog in front knows where we are all going.

The reward for running faster is to get your nose closer to the rear end of the dog in front.



Best regards



Mike Testro

This reminds me of chicken and pig story: (Copied from one of the websites, few months before)



There are several variants as to how the Chicken and the Pig meet and the level of the relationship between the two.



However, in every variant, the Chicken suggests that the two involve themselves in a scheme involving ham (or bacon) and eggs (some suggest a breakfast, others suggest a restaurant). In reply, the Pig always notes that, for the Chicken, only a contribution is required (as a chicken can simply lay an egg and then resume normal activities), while for the Pig a "total commitment" (or total sacrifice) is needed (as in order to make ham or bacon, the pig must be slaughtered).



This illustrate two types of project members: pigs, who are totally committed to the project and accountable for its outcome, and chickens, who consult on the project and are informed of its progress. By extension, a rooster can be defined as a person who struts around offering uninformed, unhelpful opinions.



A successful project needs both chickens and pigs (roosters are seen as unproductive). However, given the sacrifice required of being a pig -- forswearing other projects and opportunities - they can be difficult to collect. Thus, the construction of a successful project-team must ensure that the project has sufficient "pigs" - and ensure that they are empowered to drive the project in return for committing to and taking accountability for it.



So, guys who r u then, PIG or a CHICKEN (Chooza)?



:-)

Andy

Listening or rather reading your cri de couer reminds of the Engineer at one of NASA’s sun contractors who kept telling people about the problems with a certain 50cent O-ring. He was able to stop the launch for a few days but the Management (as you are ALWAYS right) told him he was costing NASA heaps of dollars and that he should take off his Engineering hat and put on his Management hat. The result was the loss of the Shuttle plus seven lives.



How ethical is that. What we as Planners and Schedulers need to do is to question the ethics of what management is trying to do.



The Westgate bridge design in Melbourne back in the 1970’s crashed because it had a design fault that no body in the construction company would believe. It fell down killing 34 people. Then we found out that the other four that had were being built also crashed down and that a total of 104 people died. After that the Government here in Victoria insisted on ethical design and all Finite Element engineers had to carry out certification testing and sign their name to the design. If anybody got killed then they were up for Man slaughter.



Whilst I am not proposing the same, I was taught from a very early age to get my Engineering / Construction / Project Manager to sign off their agreement to my Critical Path schedule.



When you have to sign for things this - sometimes - puts a different light on it.



It is time that P & S pushed the ethical case via this method and then see what happens.



I like the fact that you are having to fudge your results and remove the detail which makes the plan function



Same thing happened to me last year in Queensland .. umm .. is there a pattern here ...



So I quit the project, I don’t do failure and the additional cost and delays in that project are for all to see. And I can sleep at night not worrying about the short cuts (which may impact safety) needed.



However the EM, CM and PM are no longer there as the client finally understood what the hell was going on.



Just think of all the new P & S jobs now needed in Sichuan



Cheers



Raf

The project that I am currently using as an excuse to continue my therapy, has a very unique method of schedule compression.



basically all project management theory, practices, knowledge (they didn’t have this one to start with), has been tossed out the window.



We run our entire project at the whim of the engineering and construction manager.



They simply say when something has to be delivered and assume it will be.



I’ve got no reason to doubt this as they have made me strip 85% of the detail from my schedule and I’m not required/allowed to have resources in the schedule.



In fact, if I change the data date and the pretty green bars move out to the right from the pretty yellow bars, I have to stay after work and sit with the managers in question and move the pretty green bars back over the top of the pretty yellow bars, well the end dates anyway..



To say that I’ve done nothing to rectify the situation is not quite right, I live in hope that all of the noise I make is being heard and that there will be a day in the near future where they actually give me a design deliverables list that I can throw in a schedule and if I’m real lucky I’ll be able to put some resources against them.



I’ve nearly finished my degree in basket weaving while I wait for this info, and I’ve knitted 3 jumpers - well a bloke has to do something with his time at work........



Seriously though, the project is so far off the rails they just don’t want to know. They did not engage in any upfront planning at my request as they maintained that "This Project Is Being Run As An Alliance". How foolish of me then, we don’t need a plan,,,,,, It’s an Alliance - and we all know that they are the best thing since sliced bread - Don’t we.........



I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...I love my Job...



Andy

Mike



Change in methodology, production rate, remove resource related link, increase resource, reduce duration, removing access restriction... just a few that comes up in a second.



Of course there are many other way to compress your schedule.



Well you can argue that all of these is the same, changing your schedule. And you might concluded that, to compress a schedule there is only one way - change your schedule. LOL



Alex

everybody, please be informed that you can always compress your schedule using whatever technique you knew (after all, it’s only on paper or your pc) but you can never compress the real work (considering real sequencing) unless there are changes in quantities or volume of the work. so I suggest for studying Work compression techniques rather than schedule compression.

I do agree with most of the guys, but the point is, if v hav to COMPRESS a schedule, then v always look into the critical path, having zero float and activities having minimal float available.



U still require human brain to judge the resource allocation for those activities on the critical path. There is no software available, which can judge on his own to compress.



Also, nobody would like to hav uniform comprssion of all critical activities. It will vary from organization to organization and availability of resources during particular phase of the project.



There also a tern called "FAST TRACKING", wherein u can still compress a schedule by making critical activities running in parallel. There’s a risk involved, but it can be found useful only where there is good relationship among client, consultant and contractor and no BLAME GAME.



So, there are no as such MODERN compression techniques. V still compress schedule based on past experience and resources availavble during desired periof of project. Only, v can take help from these new softwares to determine critical path and doing resource allocation.



Cheers,



Rav

Gentlemen

We have seemed to have forgotten that in order to compress a schedule one needs to determine the amount of Total Float or the amount of Resources allocated to an activity.

To say that reducing a 30 day activity to zero duration did n’t do much was because that activity had only one days float.



If it is possible, the way I do it is to examine the resource loadings and ascertain whether or not I can temporarily increase the resource loadings in order to reduce the duration, and gradually work my way through the network logic. In addition I also use a technique called progressive feed which does a great job of reducing various paths.



If you do not know how to do progressive feed (or Ladders as it is called in Micro Planner X-Pert), then read HS Woodgates book on Planning by Network which was published back in 1964.



Schedule Compression - Been there and done it



Raf

Hi Stephen,



Computer and computer softwares are only tools for us to utilise to help us make our life easy. But I do not think the computer has the brains to select inteligently which activities he can compressed and which activities he can not, you still need to feed him your inputs, otherwise the computer will compressed everything indiscriminately.



What you may consider modern technique is not so modern after all because at the end of the day you still need your brain to analyse what you need to do to compress a programme.



Cheers mate,

Daniel

Hi Alex



I am always ready to learn something new - even in planning.



So if you know how to accelerate a programme other than by either changing the logic or reducing the duration of the activities or both then my eyes and brain are open to receive.



As I have said before the art is to do both and retain the integrity of the programme.



There have been a number of times when my employer has asked me to "knock off" a couple of months so that he can "get the job".



I do the best I can to get as near as possible to his target - telling him the risk and cost implications - but if it can’t be achieved at all then he can look for another planner before I put my name to an invalid programme.



That is one advantage of working as a freelance consultant.



Best regards



Mike Testro

Hi Mike,



I have to agree with Stephen, there is certainly more than two ways to achieve the same goal. And we cannot ignore something just because we don’t have the knowledge.



I am sure with 45years of experience, you did see a lot, but cannot be everything.



What Stephen describe is what I call acceleration technique. And certainly not just changing logic or increase resource.



Please don’t take it personal, we as a PPers have to keep our view/mind open.



Good Luck



Alex

"I have never yet read any books on planning techniques and I do not mean to start now."



Then, Mike, there is certainly no grounds for us to debate.



Cheers.

Hi Stephen



What you have said is another way of saying:

"The art is in changing the logic and shortening the durations and still retain a viable programme"



As I have said before in another forum I am not a planner - I am abuilder who can do the software.



Having been abuilder for 45 years I know how things are put together.



I have never yet read any books on planning techniques and I do not mean to start now.



The one acronym that I do follow is the KISS system - Keep It Simple Stupid!.



That butters my muffin.



Best regards



Mike Testro

Hi, Vinod; hi, Mike.



Mike, at base, you are of course correct when you say that the only two ways to compress the schedule are to change logic and/or durations. But that’s a bit like saying that the only way to make a baby is to have a sperm make contact with an egg -- undoubtedly true, yet there’s an awful lot of what you may term "art" in accomplishing that goal! Some techniques may be more or less successful in different contexts. (Genghis Khan was evidently very successful -- but most of us would probably not experience long-term success by using his approach!)



Schedule compression is hugely valuable. The more assistance we can give the scheduler by pointing to places where crashing or fast tracking might be more productive, the better. Obviously, the simplest such pointer is the critical path, as all the duration and logic changes in the world will have no impact if applied to work that has float.



Unfortunately, PM (and PM software) is not very helpful in pointing to activities that are fertile for compression. A 30-day activity on the CP may be reduced to zero and the project duration may change by only one day. Conversely, another CP activity may have a duration of just 8 days -- but by halving that duration to 4d, we may be able to gain the full amount of the activity reduction on the project duration. The concept at work here is DRAG, the amount of time a CP activity is adding to the project’s duration. And while it’s easy to see and compute in a small project network, it gets bloody hard in 5,000-activity schedules with lots of complex dependencies! (This in fact is one way I make my living!)



A second useful pointer is DRED, or the Doubled Resource Estimated Duration. This is a measure of an activity’s "resource elasticity". Even if a CP activity has lots of DRAG, it’s not always possible to shorten its duration economically. Some activity durations are a LOT less impacted by added resources than others, and that’s useful information to have when trying to compress a schedule -- how much would added resources shorten an activity’s duration, or would they leave it unchanged or even make it longer (the latter being a situation I recently experienced dealing with work to be performed in the cockpit of a jet; not much room in there!)?



The third acronym is the CLUB, which is the Cost of Leveling with Unresolved Bottlenecks. It is not a metric for helping compress an individual project schedule, but rather for helping an organization identify those resources that repeatedly wind up with DRAG on the resource-loaded CP. By measuring how much the delays due to the lack of such resources is costing, the individual project can often justify the cost for more such resources. And the whole organization can start targeting the specific staffing shortages delay are delaying its projects.



The best resource for all this is probably my book Total Project Control (John Wiley, 1999), but there are some web-based articles. Unfortunately, the best article "Scheduling is a DRAG!" by Bill Duncan (author of the 1996 edition of the PMBOK Guide) is temporarily not available -- it was published by ChiefProjectOfficer.com whose site is now defunct. Projects@Work.com has taken over their articles, but not yet put them on-line.



However, there are six articles by me in the Methods & Means subforum at Projects@Work that explain some of this. If you go to the site and do a search on "devaux", you’ll see them. (You have to register on the site, but it’s free.)



The URL is:

projectsatwork.com



You can also get more info at my Total Project Control website. There is a little exercise on how to compute DRAG in a very simple (FS) network at:



http://totalprojectcontrol.com/exercises/exercise2.html



And another diagram shows DRAG computations in a more complex network at:



http://totalprojectcontrol.com/tpc/tpc.html



As an aside: Mike, I think you’d find automated DRAG computation extremely useful in As Built Critical Path analysis for forensic purposes.

3. if you are the Client, always make the contractor happy, if it is a Contractor in good faith, he will do the same to you

Hi Stepehn Hi Vinod.



I have no idea what you are talking about.



There are only two ways to compress a programme:



1. Change the logic.

2. Shorten the durations.



The art is to do either or both and still retain a viable programme.



Best regards



Mike Testro.

Daniel Limson wrote: "There is no such thing as ’modern schedule compression techniques’ "



Daniel, I have to sort of disagree -- depending on how one defines "modern" and "techniques". TPC metrics have only been around for about ten years. But I think I would define the use of metrics such as DRAG, the CLUB (Cost of Leveling with Unresolved Bottlenecks) and DRED (Doubled Resource Estimated Duration) to optimize a schedule as "modern schedule compression techniques".

you can add bonus / incentives (in writing!)to make the contractor happy!

There is no such thing as "modern schedule compression techniques" It has always been common sense and careful strategic planning. If you want to compress a programme, you need to increase production. hence, you need to increase your manpower or resources or maybe improve the system or methodology. However, there maybe some contraints (like space) and you must examine carefully which activities you can accelerate especially activities falling on the critical path. Some works are progressive in nature and you can only use one Gang to progress the work. There are some activities you can accelerate by adding multiple gangs to perform the work thus compressing your programme.



The other way is by improving the system or methodology for example instead of cast in-situ you precast some members of the structure to accelerate work or by re-sequencing the works or phasing the area to follow on works.



Cheers,

Daniel

I am asking a dump question , is that mean acceleration schedule??

Similar story to James in Nuclear, if you really want to shorten your Critical Path, you need to ensure that you you have is a sufficiently detailed, logically robust programme (without, perhaps, going as far as scheduling toilet breaks... I have seen it done).

Once you have a programme you can happily stand by (rather than what I term as ’Reporting Programmes’), then you can start challenging the logic, and durations.

If you’re doing it properly you’ll start to get to the stage where you’re trading critical paths (shortening the critical path and being presented with the next sub-critical path as the CP, and the next, and then back to the first etc. etc.) When you get to this stage, you then can produce a histogram to see just how much of a tall order your new programme is. Then you’ve got to sell it, and that’s the good bit ;o)

I don’t know a better tool than the correctly applied planner’s mind for squeezing timescales. The more detailed your plan, the more closely you can study it.



"crashing" a high level plan would require SS relationships and (gasp) negative lags and this sort of thing and is heading for trouble, imo. Break the plan down further until you can schedule it properly, then see where the gaps are.



We have on average one activity per man-shift. Of course this takes a lot of effort and investment in the plan production, which I have not seen a project outside of O&G put in (and I had 15 years exp before starting in O&G). Without very high level backing you will never get this kind of investment.



Try breaking down just your critical path to get a better view on that. And remember; there will always be a reasonable minimum, beyond which you are in what is technically termed "Lah Lah Land" ;)

Hi Vinod



The best way is to use ladders in Arrow Diagram Format.

But the catch is only Micro Planner X-Pert still runs Arrow diagrams.



You can compress schedules by very carefully using Start to Start and Finish to Finish links. But MSP. P3 and OPP all calculate SS and FF badly and you finish up with Lag Drag and instead of shortening the project duration you extend it.

Raf

Hi All



I understand now - it means shortening the time period.



Thank you.

I assume you are talking about ’crashing the critical path’? I am not aware of any ’new’ techniques. The steps have always been - (1) examine the critical/sub-critical paths for realistic duration reduction/network logic changes (2) examine the effects of (1) on cost, ability to meet the ’crashed’ schedule, availability of extra resources etc.

Hi Vinod



I have no idea at all what you are talking about.



Please elucidate.



Best regards



Mike testro