After 25 years of project controls, I find my self at a lost for any new words that would help my current construction project team decide when it is appropriate to re-baseline the schedule and schedule performance data. Can anyone provide me with thier own general rules of thumbs or even better direct me to quotable source in the industry? General overview: multiple primes; design build with design recently completed; construction at ~ 60%; there has been signficant budget changes since the 1st and only baseline a year ago; current float is signficantly less than original baseline; approx 9 months to go with the most difficult construction remaining.
Thanks in advance for your input and help.
From the inputs you have provided, it looks like that you are doing fine. And, no need to panic or re-baseline.
My justification, based on the inputs provided by you,is as below:
1.First & original base line was done 1 year ago.
2.You have 9 months to go
3.The cumulative progress as of date is ~60%
Now, let us see the appx. status of the project as of date:
Total project completion time(computed)=12+9 = 21 months
Progress achieved = ~60%
Remaining work = ~40%
Remaining duration = 9 months
Schedule Variance, SV = EV - PV
= 60 - 57
( on pro-rata basis,
PV as of today = (12m/ 21m)x100
PV= 57 )
SV = 60-57 = +3
A + ve sign of schedule variance, SV, indicates that you are, in fact,ahead of schedule or just on schedule.
I have assumed that the all the activities/works on the critical path are of equal weightage in terms of their difficulty level.
On the contrary, if your statement that most difficult construction works remaining are to be completed in 9 months is true, then your claim of 60% progress as of date is overstated or to be re-examined.
In my opinion,the difficulty level of the works/activities must have already been taken into account by estimators while estimating the duration for those "difficult" activities and if those of difficult activities lie on the critical path then also you need not worry as the time required for completing them have been already considered in the original baseline critical path.
If the remaining difficult activities are not on critical path, then they will have floats and you get more than sufficient time to finish them off w/o affecting the baselined project completion time.
Hence, you are on target, if not ahead of schedule and hence no need to re-baseline.
Hope this helps.
Here is some excerpte from paper titled "Risk Review of Recovery Schedules" presented recently in Toronto :
"Under standard CPM scheduling practice, the baseline schedule remains in effect until there are substantial changes to the plan that affect the critical path (i.e., delays). When the project experiences delay, the contractor is typically required to prepare a Recovery Schedule that demonstrates how the lost time will be recovered. As such, recovery schedules are often used when the assessment of liquidated damages is a risk issue. Typically, a revised baseline schedule is necessary when:
• The critical path changes as a result of major delays and/or scope changes,
• Delays have consumed the total float on non-critical activities and pushed them into the critical path,
• The project schedule does not accurately reflect the actual planned execution, project scope or progress of the work, or
• The project is performing major out of sequence work.
The Association for the Advancement of Cost Engineering International defines the Recovery Schedule as “A special schedule showing special efforts to recover time lost compared to the master schedule. Often a contract requirement when the projected finish date is no longer showing timely completion. (6/07)” .
While the construction industry is more often including recovery schedule requirements in contracts, these contracts contain a variety of conditions under which a recovery schedule is required. The following examples illustrate the varying contract conditions that define the need for a recovery schedule:
• If the project falls behind schedule more than 14 days or 10% of the remaining duration, whichever is less, for non-excusable delays;
• In the event that the Progress Schedule Update indicates that the Project, or progress towards any interim milestone, falls 20 or more work days behind schedule;
• When requested by the Owner or Engineer;
• When the owner determines that the contractor is behind any mandatory specific milestone or completion dates or any interim milestone completion date;
• When the contractor determines that the progress schedule requires revision for any reason; and,
• When departure from the existing schedule makes it apparent that the project will be late.
In addition to the “triggers” for determining the need for a recovery schedule, there are other considerations with respect to developing a recovery schedule. First, the need for a recovery schedule should consider any excusable delays or changes and all time extensions to which the Contractor is entitled. Second, the timing for submittal of the recovery schedule can also be specified. For example, some contracts require that a recovery schedule shall be submitted 14 calendar days after the monthly progress schedule update was submitted. Further, some contracts allow for the Owner to withhold progress payments until the Contractor submits a revised recovery schedule, acceptable to the Owner. When specific contract language exists, but the Contractor fails to produce an acceptable recovery schedule, there may be breach of contract issue. The refusal, failure, or neglect to take appropriate recovery action or to submit a recovery schedule could constitute evidence that the Contractor was not diligently prosecuting the work and could be considered grounds for termination. Finally, the Owner is typically entitled to direct the Contractor to prepare the recovery schedule at no extra cost to the Owner."
I hope this helps.