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Presenting critical path when planned completion is prior to contractual completion

6 replies [Last post]
Bo Johnsen
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If planned completion date of a project is prior to contractual completion date, how would you most correctly show the critical path throughout the project?

Say the contractual duration of a project is 24 months and you plan to complete the project in 21 months, i.e. 3 months before, and you show this in the submitted programme. Initially, there will be no critical path because the “real critical path” up to the planned completion date will have 3 months total float, so no activities will appear critical.

Option 1: Make a lag between “Planned Completion Date” and “Contractual Completion Date” of 3 months, thereby getting the critical path.

Option 2: Make the above lag a task instead of 3 months duration and e.g. call it “Contractor’s Time Risk Contingency” (probably only a valid term in a NEC contract?)

Option 3: Add a soft finish-constraint or deadline with the actual date of the planned completion date? Don’t like this option as the specific date has to be changed every time something else changes in the programme.

Option 4: Tick the milestone for “Planned Completion Date” as being “Always Critical” (total float constraint), however, not all planning software packages have this nice little feature for situations like this.

Option 5: Just leave the milestone for “Contractual Completion Date” out of the programme as all parties know that 24 months is the contractual duration, thereby only showing the programme with a 21 months duration (=as planned).

Option 6: Other?

Concerning option 1-4, the disadvantage is that the Project Summary bar (very top line) will show 24 months instead of 21 months, unless you keep the milestone for “Contractual Completion Date” as a separate little item (outdented to Level 1) below the main programme (presentation wise this looks silly). And showing the 24 months for the Project Summary Bar is maybe not the best thing in a tender situation where people not that well versed in Gantt charts are looking at you rolled-up 1 A4-page presentation of the project.





Rafael Davila
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Never show all your cards to an owner that does not allows you to plan your way. If he insists in a lie, then give him a lie. Try to abide by the contract as any good contractor will, target for early finish in the hope of finishing on time. Sorry it is too much for him, his lawyer and the courts to understand this shall not be interpreted as an implied change in contract conditions.

Just be real and play it by the rules,  but wisely and always keeping control, don't be a fool, better fool him.

Rafael Davila
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Just take a look at the following screen capture for an example on how calendars can bring surprises.

 Gantt shall be able to display available calendar times for activities as well as for resources and teams, for uncompleted activities up to project finish date.   

Expanding to Availability might display a line for quantity assigned to this activity, a line for quantity assigned elsewhere and a line for quantity idle.

Then you will be able to see why next week a team of 20 will not be able to work because a single resource is on vacation at Panama City. This and similar issues will be visible on the spot.

Mike Testro
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Hi Bo

Another method is to add a single task called "Forced Critical" which is linked FS to the last task in the programme with a duration that exceeds the required completion date.

In most software this task can be hidden on print.

Best regards

Mike Testro

Rafael Davila
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Just look at the following schedule if using Longest Path activity 3 will be ruled out, while because of calendars it has no float, it cannot be delayed a single second without delaying the job completion.

Longest Path

I particularly have my reserves about Longest Path, not only because of calendars but also because of resource leveling. I do not believe it to be the answer to the quest for the perpetual motion machine. Still useful, but use it wisely.

No matter how you look at it if you want to see Critical Path just eliminate Finish Date Constraints and this includes project finish constraint or use software that do not fool the model as to make the impossible possible, late dates earlier than early dates.

Come on, negative float yields impossible values, is impossible, is wrong modeling. Just that it is a mathematical computation does not justifies it, is crazy.

Best regards,


Gary Whitehead
User offline. Last seen 2 years 19 weeks ago. Offline

It depends on what software you're using, but if it's P6, I would:


-Delete the contractual milestone, and replace with a project completion constraint

-Define critical activities as longest path in your scheduling options

Rafael Davila
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Joined: 1 Mar 2004
Posts: 5065
If you are free to plan your job you should be free to plan it your way.

If because of the lawyers and their interpretation of what such schedule submittal means then I would keep two schedules.

I would have an optimistic version without any contingency whatsoever, no buffer, no rain allowance, no finish date constraints and with optimistic but feasible durations. This I would use it to manage the day to day operations, a schedule without any obstruction to my view.

I would keep a probable version that uses all contract time, this with all contingencies and required finish date constraints. If you have statistical analysis functionality in your software you could even figure the probability of such plan finish on contract date. This I would use it to manage the Contract, a schedule that tells about the contractual dates.

If in order to effectivelly manage your job you need the optimistic version then why not to strip it of all fat?

I use Spider Project, a software that allows me to keep shyncronized both versions at a click of the mouse.

Import Performance

Guess this makes it to be "Option 6".

Best regards,