The Critical Path
On baseline durations, this project will take 31 weeks to complete.
Taking November 8, 2010, as the start date and assuming the default of four weeks each month (instead of the reality that is 13 weeks per quarter), the baseline ending date would be the week of June 26, 2011.
The critical path (see Exhibit A) is defined by this succession of activities:
- Finalize site and building contracts.
- Select a local printer.
- Design promotional Web site.
- Set a TV deal.
- Hire director.
- Plan for TV camera placement.
- Passes and stage credentials.
Crashing the Project
A delay of two weeks in Activity B, since it is on the critical path, delays project completion by the same duration (Exhibit B). To keep the rest of the project on schedule so that everything is ready on the last week of June 2010, it is advisable to be vigilant about project monitoring, ensure commitment by lead resources, see to timeliness and accuracy of status reports. More specifically, Lever (2009) recommends a calibrated approach whereby the first delay in a task on the critical path triggers an immediate offer of help, the second delay requires the project manager to help outright, and third calls for a re-assessment meeting by all stakeholders concerned to go over the options.
Another solution, notably in the commercial building trades, is required when the asset or building owner issues a change-work order. Despite the obvious reluctance of project engineers and architects to commit themselves, the owner or project manager would do well to have them complete AIA Document G-701, one clause of which reads “The architect is to confirm that contract time will be increased, decreased or remain the same with the execution of this change order” (Levy, 2006, p. 189).
Among the “self-evident” solutions, increasing (manpower) resources for the stages dependent on Activity B is not a failsafe solution. This is because new team members need to be brought up to speed. Hence, they are not immediately as productive as one would expect. Further productivity is lost when veteran team members take time away from the project to conduct on-the-job training (Biore, 2010).
On balance, the optimal options would seem to be:
- Prioritize those on the critical path.
- Re-scan the work breakdown structure and PERT Analysis to see which of the start-to-finish links can be broken if they can start once an earlier activity has finished. This usually means that the re-cast activity can run simultaneously with that on which it was formerly dependent. More rarely, the rescheduled activity might even take advantage of earlier start date. In the “crash” version (Exhibit C), we realize on reflection that Activity D, “Design promotional Web site”, really need not wait on Activity B. “Select the local printer” to commence. We can therefore designate Activity D to commence once Activity A is completed.
- We then proceed to scan the rest of the critical path for activities where the time saving is optimal by a larger difference between “crash” and “normal” times. This is key. As a bonus, it would be great if the incremental cost of enforcing a crash schedule on that activity was comparatively low. An excellent example, it turns out, is Activity O, “Passes and stage credentials”, were turning to “crash” mode recovers the two weeks lost in Activity B while incurring a minimal cost penalty of $1,800. The cost impact is minimal in point of both absolute dollars (the cost penalty for crashing Activities A or D come to $3,000-$4,000) and relative to the overall budget (a mere 1.8% overrun on the original project budget of $99,900).
Where step C above makes up fully for the delay caused by Activity B, the fine-tuning done on Activity D achieves an earlier finish time for the entire project, to the week of June 12, 2011.
References
Biore, B. (2010). About project crashing (shortening a project schedule).Web.
Lever, R. (2009). Project tracking and managing project time delay. Web.
Levy, S. (2006). Project management in construction. New York: McGraw-Hill Professional.
