PERT Variability
Jim Sabatke <[email protected]> Tue, 11 Apr 2006 18:10:22 -0500
| Newsgroups | gmane.comp.kde.kplato |
|---|---|
| Message-ID | <[email protected]> |
Hi all, First, congrat's for getting out a first version!!! When we first started discussing this project, we spent a lot of time on PERT statistics. In my opinion, PERT charts are a waste of a LOT of paper, but the statistics are extremely useful and separate a mediocre planner from a truly useful one. They are also easy to understand and calculate. They also (usually) give much more accurate resulting delivery times than hard durations. Another very valuable tool is the charting of certain project variables. The most useful: 1. Budgeted Cost of Work Scheduled vs. Actual Cost of Work Performed. This gives the schedule variance. You can show this to your manager or team and disclose if the they are behind or ahead of schedule/cost. You all probably realize that in software projects especially, that often tasks are done out of order for various reasons. Therefore, GANTT charts are often deceptive. When building a bridge, concrete HAS to be poured and cured before starting steelwork; but in software the tasks are often just a collection of things that need to be done, often in no particular order. 2. Actual Cost of Work Performed vs. Actual Cost of Work Scheduled. This is the cost variance. Are we delivering this project at the defined cost? Attention to those two graphs will give notice of disasters while there is still time to correct them. They also give 'paperwork' to managers that they can easily understand when they ask if the project is on time and within budget. Managers don't want to hear about task variability as a rule, so these, plus GANTT charts, tend to placate them. As one of the originating 'thinkers' on this project, I am very happy to see it moving forward. Regards, Jim