Schedule Variance ( Progress Figure) & Negative Float

  • Page:
  • 1

Schedule Variance ( Progress Figure) & Negative Float

OFFLINE

Schedule Variance ( Progress Figure) & Negative Float

22 October 2010 5:15
In EPC Projects the procurement activities weight is quite high , hence when all the material arrived on site ahead of schedule the overall project progress figure will look fine . however , if there are major delay on some engineering items which is heavily affect on longest path, these impact will not be reflected on the progress figures but it will appear only as negative float on the program . Therefore , I think in EPC Contract the schedule variance (Progress Figures) are not enough for project evaluation .It may mislead the management if the negative float is not considered Do you agree ? What is your common practices in term of reporting ?
OFFLINE

Re: Schedule Variance ( Progress Figure) & Negative Float

22 October 2010 5:16
In my experience, yes, the procurement items do weigh in on the overall progress measurement but I analyze the entire critical path and that will include procurement items that may have been on the critical path (especially, long lead items). There is never just one critical path...there are parallel critical paths that need to be analyzed. One killer of critical path analysis is the use of constraint dates and open ended tasks. Verify the logic along the most critical path, clean the negativity up and put the schedule back in line. Hope this helps.
OFFLINE

Re: Schedule Variance ( Progress Figure) & Negative Float

22 October 2010 5:17
Yes, progress should drive the schedule. You are not in a problem, but want to avoid one. You want the schedule to report problems long before they impact the work. Showing the impact of negative float is your function. Digger is a great tool for schedule validation. It will give a detailed comparison and analysis of the schedule logic, open ends, out of sequence work and statused tasks so you can make repairs or update status. Be sure that any corrections are included in your next submital narrative, since the schedule is a legal document. Ditch all constrained dates, including final completion so the schedule is completely calculated. If your schedule never completed on time without constraints, it is time to figure out how you can. Calculate with retained logic instead of progress override. Run longest path to completion reports and resolve each problem until completion on time is calculated. Do six month look aheads filtered for procurement or engineering activities for your schedule and construction meetings. Hold the suppliers (or engineers) of long lead items to their submitted schedule and apprise them of the costs of their delays in order to let let them adjust their schedule to get back in compliance. If the item is late due to changes, advise the owner of the impact of their decisions on completion and contractor costs. Achieve the schedules previously constrained dates if necessary through acceleration by adding resources to shorten durations of predecessor tasks or giving linked predecessor tasks start to start relationships with lags where possible determined in acceleration meetings with crew chiefs.
OFFLINE
Joined On:
30 Sep 2017

Re: Schedule Variance ( Progress Figure) & Negative Float

22 October 2010 5:18
Its really pretty simple. You have to monitor the critical path because that is where the immediate delays will appear. You have to monitor the near-critical path because that is where delays will take over the critical path, likely in a mid-period critical path shift that will occur between updates and could take you by surprise. And you have to monitor the non-critical path because that is where disruption happens, where work slips to the end of the project and stacks up, and where significant disruption and delay will occur while you are watching the critical path, especially if the network is not really well done. The lack of good resource logic often causes many of the non-critical path problems. Without resource logic, similar trade work will be allowed to stack on the schedule, while no one really watches to see that the schedule now shows a need for three electrical crews, then four, then seven, then nine, until rapidly there are not enough resources to work concurrently on all the activities needed. With poor resource logic, you cannot count on float dissipation reports, you cannot count on critical path analysis, and the only remaining way to monitor is for good, trade and location specific earned value monitoring. Even then, it is likely that the project will not provide adequate early warning of resource problems. I suggest that all schedulers run a late date sort on their baseline schedules, then organize the schedule by week, and starting at the end of the project, look at how much work is planned to happen every week, especially in similar trades and specific locations. Usually, I find that the baseline plan is unworkable, so that all it takes is a couple of minor slips in progress to put the project schedule in a position where concurrent work by trade and location is overwhelming. If engineering, procurement, and owner responsible work are all missing or inadequately modeled, the network is not capable of providing the robust and effective monitoring tool. Comment from Moderator: The part of this comment has been picked up by external website and originator "Richard" has been warned about the same. We suggest all our members to be original in their responses and avoid plagiarism.
Last Edit: 10 years ago by . Reason: (NULL)
  • Page:
  • 1