Guild of Project Controls: Compendium | Roles | Assessment | Certifications | Membership

Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

SCHEDULING WITH CONSTRAINTS

19 replies [Last post]
ALKA REVO
User offline. Last seen 11 years 23 weeks ago. Offline
Joined: 23 May 2007
Posts: 20
Hi, Have been working on Primavera for long time. Now new client wants me to work on MSP.Iwant to put finish no later than constraint on some activities in an existing plan and reschedule the plan to see how it moves.But MSP is not allowing to schedule with any constraint at all.
Any suggestions?

Replies

Mike Testro
User offline. Last seen 30 weeks 5 days ago. Offline
Joined: 14 Dec 2005
Posts: 4418
Hi Raphael

It was youre thread.

We have Raphael and Rafael. - I spelt the wrong one.

Best regards

Mike Testro
Raphael M. Dua
User offline. Last seen 11 weeks 1 day ago. Offline
Mike
In your response, were you referring to me Raphael or the other Rafael in Puerto Rico

By PP I meant Planning Planet

I have just looked back at few of my recent posts, I think I going to work down your path ....

Raf
Hemanth Kumar
User offline. Last seen 1 year 16 weeks ago. Offline
Joined: 1 Nov 2002
Posts: 260
Groups: None
I Have a Custom Tool Buttom With a macro which makes all activities constraint type as "as soon as possible "
i press this button every now and then, MSP is a wonderful software to make massive initial plans , make plan just import to P6 or from there export to P3

i make all my plans in MSP ( average 5000 Activities) and run in P X
Mike Testro
User offline. Last seen 30 weeks 5 days ago. Offline
Joined: 14 Dec 2005
Posts: 4418
Hi Raphael

It is not much of a consolation but there are programmes out there which are much worse than PP.

Project Commander - Fastrak - powerproject lite to name a few.

Best regards

Mike Testro.
Raphael M. Dua
User offline. Last seen 11 weeks 1 day ago. Offline
Folks

Goodness me

It is time people learned to plan without the need to force an answer.

I almost NEVER use constraints, I have a contract which is full of them and thats where they belong.

I plan my tasks with resources and durations such that I can get my milestones to occur from the forward pass to be where they should be.

No matter what software you use, if you use constraints to force the software to give you the answer you claim to know that it should be, what you are doing is welding bits of rebar fore and aft of your tasks where the rebar represents a time of varying lengths and being all surprised when the end task is out into the future past the required end date.

I am with both Mike and Trevor, MSP is a schizophrenic piece of software. Both Crap and OK

Some people spend the time in understanding how to plan and schedule using Gantt charts and can apply MSP to produce an answer.

And without a doubt (from all of the to and froing of hate, love etc for MSP) most people CANNOT actually use MSP, because they have been conned, brainwashed or what ever into believing MSP is "Simple to use and you can produce a plan in minutes",

Well my friends as I know from over fifty years of Planning & Scheduling , as well as writing Critical Path software for use in planning and scheduling, MSP is probably the most COMPLEX piece of programming ever produced.

There are over 500 different blogs, expert help pages etc on MSP, with well over 200 million pleas for help and asistance trying to get MSP to deliver.

Thus, Bo, if it was easy, there would n’t be anywhere the need for those pages

If you want to run a proper project plan, with Resources, Multiple Calendars and Date constraints that work and want to do Earned Value you should be using Micro Planner X-Pert for Windows.

At least it is predicated on Critical Path practices and Principles as design by Kelly & Walker back in 1956/7

Phew, you got me going again, I swore blind I was going ignore PP, but too many people now have my personal e-mail and keep on asking why I don’t respond ..... now you know

Raf
Bo Johnsen
User offline. Last seen 8 years 33 weeks ago. Offline
Joined: 28 Feb 2006
Posts: 119
Hi Mike,

"...I have learnt a lot from it..." - I was almost sure I couldn’t teach an old dog new tricks.

Cheers,

Bo
Mike Testro
User offline. Last seen 30 weeks 5 days ago. Offline
Joined: 14 Dec 2005
Posts: 4418
Hi Bo

Thanks for that dissertation - I have learnt a lot from it.

I used the word "crap" to see what response there was out there.

It seems the replies are currently balanced 50/50.

Best regards

Mike Testro
Bo Johnsen
User offline. Last seen 8 years 33 weeks ago. Offline
Joined: 28 Feb 2006
Posts: 119
Alka,

A FNLT constraint should not move a task up to its latest finish date, it just tells when it latest can finish – not must. So if you are telling us that P6 is giving you “when to start your first activity latest when applying a FNLT to the last activity” I would state that P6 does it wrong. What you are looking for is probably the ALAP in combination with the FNLT: Apply FNLT to the last activity and ALAP to the first one in your series of 10 tasks and you get the result you want in MSP. Ok, admitted, the ALAP function doesn’t work correctly in MSP as it consumes total float – also for successors, so you can’t use the above solution in other software packages. Here you probably have to apply ALAP to all 10 tasks. And when having more than just 1 series of tasks in MSP, you have to be very careful (read: never) when using the ALAP in MSP. Another solution in MSP is just to pull up your “latest start” column – and maybe even add a bar style for this on the Gantt chart.

When that is said, this is about the only disadvantage that MSP has concerning constraints IMO – well, it maybe is also missing a feature for zero free float constraint and zero total float constraint (i.e. always critical). With respect to all the cons Alexandre is listing, for me it is simple logic that as soon you start to mess around in the start and finish columns + drawing any tasks on the Gantt chart you are dealing with some kind of constraints, so I never (or as close to) operate in these locations – except maybe for some special start / finish milestones now and then. As I rarely (deliberately) have constraints in my programmes I basically only operate in the “Task Name”, “Duration”, Predecessor” and “Successor” columns. I find it very cumbersome and slow to draw tasks and links directly on the Gantt chart, so when working in e.g. PowerProject or Pertmaster (I simply won’t call it by its new name), the predecessor and successor columns are always visible and presented so links can be written easily here. Use of constraints is a “try-to-avoid” for me.

IMHO, MSP is the most user friendly system of them all. Anybody with no prior knowledge of planning software systems can within a few hours produce a simple programme in MSP, which would take a day or days in other planning systems, so therefore MSP (in construction) is good for many site engineers, agents, foreman, supervisors, engineers based in office, etc. that is only doing programming “now and then”. i.e. not 100% planners. Furthermore, it is cheaper than many of the other systems on the market. MSP is not “specialist friendly” (or “delay / claims”-friendly) because its lack of features and at certain times lack of sound theory, but that doesn’t mean it is not user friendly. Moreover, the auto-filter function and customized fields function are 2 very user friendly features I miss very much when utilizing other systems – but then again, MSP lacks a lot of nice features which e.g. Powerproject and Pertmaster contains.

With respect to the situation Rafael mentioned with “expected finish constraint” I’m almost certain something similar can be simulated in MSP by use of customized fields with an iif-formula, expected finish date minus early start date, maybe a flag and maybe a user made bar style (again with a flag) to show the result required.

Sorry it became a bit too long, but I’m fed of people slagging of MSP so easily, if they haven’t spent enough time investigating its potential. Admitted, it is not the best system, but it is definitely not crap.

Regards,

Bo
Trevor Rabey
User offline. Last seen 1 year 47 weeks ago. Offline
Joined: 29 Nov 2005
Posts: 530
Groups: None
This stuff is easy in MSP too, but not if you are basically doing it wrong, and especially if you don’t have a good understanding of the Critical Path Method, what it does, what it is for etc.
CPM is about scheduling forwards from a known(or assumed)start date, and building a network based on the durations and predecessor relationships. CPM only (generally)requires FS0 links. The further you depart from straightforward FS0 links the trickier it gets.
The objective, and it is important to keep this in mind, is not to find the start date, but to find the finish date.
If you already know the finish date you don’t need the software.
Why did you link the 10 x tasks together FS in the first place?
So that MSP can find the (earliest) finish date for you, which it has done.
But you seem to have found the finish date, and found it not to your liking (because you have an earlier one in mind) and jammed a FNLT on it.
You have not told MSP to move the start date back to allow the middle part to fit, so why should it assume that’s what you want? You say, contrary to the evidence and everything ever written about planning, CPM and MSP, that it should move back the start date. Why? It shouldn’t, it can’t, it won’t.
But it does try quite hard to help you, by warnings and prompts, but you ignore or misunderstand the warnings and prompts.
When you jam in the FNLT (say 10 days earlier than what the CPM says it can happen) on the last task, this causes all of the CP predecessors to pick up negative slack (float). You can see the slack in the Schedule Table. If your first task has -10 Days of total slack, MSP is trying to tell you to move the start date back 10 days. Try working with the tool instead of against it.
ALKA REVO
User offline. Last seen 11 years 23 weeks ago. Offline
Joined: 23 May 2007
Posts: 20
I do feel that MSP is not user friendly. You have to look at everything manually, like jumping to predecessors and sucessors. Now The problem I am facing is that eg. I have 10 activities in series with FS realationship, I have a FINISH NO LATER THAN constraint on 10th activity, when I schedule the plan should tell me when to start my first activity latest. But MSP is not allowing me to schedule with this constraint. It suggest to change constarint to START NO EARLIER THAN which just moves that single activity giving lot of float btwn the activity and its predecessor.Not the desired result. This stuff is easy in P6
Rafael Davila
User offline. Last seen 1 week 1 day ago. Offline
Joined: 1 Mar 2004
Posts: 5240
I use SureTrak; one of the constraint types I frequently use to automate updating of long lead deliveries within my monthly updates is expected finish constraint where remaining duration is calculated from early start to this constrained date. How you model this in MS Project?

Best regards,
Rafael
Trevor Rabey
User offline. Last seen 1 year 47 weeks ago. Offline
Joined: 29 Nov 2005
Posts: 530
Groups: None
Mike, it’s no trouble, really.
The Indicators Column, which should always be visible, shows a little icon, with an explanation when hovered over, when there is a date constraint on a task, without having to go to Task Information.
Also, if dragging the bars causes a date constraint, as we know it does, and if that is not what is wanted, here’s a tip, don’t do it.
Intuitive? what is, really? Do I complain because my guitar is not "intuitive" (ie I can’t play it without study and practice so that I understand it)?
Perhaps Alexandre’s advice should be "be careful to read what’s in front of your face, that’s why it’s there.".
Mike Testro
User offline. Last seen 30 weeks 5 days ago. Offline
Joined: 14 Dec 2005
Posts: 4418
Hi Trevor

Alexandre has just given you one example.

The system is just not user freindly or intuitive.

Regarding constraints - if you draw a new task it puts a constraint on it by default - I have not yet found how to switch this off or change the default.

In most systems you can see if there is a constraint on the task - P3 even has an asterix and Powerproject shows a relevant flag - in MSP you have to go and look at the task info.

Another matter is the date and duration default format - never yet found out how to change it.

Please don’t go to any lengths to show me how - I only keep the software so that I can convert programmes to Pwerproject.

Best regards

Mike Testro
Trevor Rabey
User offline. Last seen 1 year 47 weeks ago. Offline
Joined: 29 Nov 2005
Posts: 530
Groups: None
Mike,
As you know, I agree with you about most things such as the abominations and the FS links.

How about just one example of MSPs alleged inferority, besides just generally slagging it off?
In my experience the "crap" is what gets produced by the user, and the software makes no difference.
Mike Testro
User offline. Last seen 30 weeks 5 days ago. Offline
Joined: 14 Dec 2005
Posts: 4418
Hi Alka

Right click the task > Go to Task Information > Advanced > Constraint Type and select the type you want.

Good lick with MSP - its a crap piece of software - much worse tha P6.

Best regards

Mike Testro