project scheduling with crashing and fast tracking
视频信息
答案文本
视频字幕
Welcome to our introduction to project scheduling. Project scheduling is a critical component of project management that involves planning activities, estimating durations, sequencing tasks, allocating resources, and meeting deadlines. The diagram shows a simple project network with four tasks. In the following scenes, we'll explore techniques to optimize this schedule, specifically focusing on crashing and fast tracking methods.
Before we can optimize a project schedule, we need to identify the critical path. The Critical Path Method, or CPM, identifies the longest path through the project network, which determines the minimum project duration. In our example, the critical path follows tasks B and D, with a total duration of 9 days. These critical activities cannot be delayed without extending the project timeline. Any optimization efforts should focus on these critical tasks to reduce the overall project duration.
Project crashing is a technique used to shorten the project duration by adding resources to critical path activities. In our example, we've crashed Tasks B and D, reducing their durations by one day each. Task B was reduced from 3 to 2 days, and Task D from 6 to 5 days. This has shortened our critical path from 9 to 7 days, a 2-day reduction. However, crashing comes at a cost - in this case, an additional $5,000. Project managers must perform a cost-time trade-off analysis to determine which activities are most cost-effective to crash.
Fast tracking is another technique to shorten project duration by performing activities in parallel that would normally be done sequentially. In our example, we've started Task D when Task B is only 25% complete, rather than waiting for Task B to finish. This overlap reduces the critical path duration from 9 to 7.5 days. However, fast tracking increases project risk. If issues arise in Task B after Task D has started, rework might be needed. Fast tracking doesn't necessarily increase direct costs like crashing does, but it requires additional coordination and may lead to quality issues if dependencies aren't properly managed.
Let's compare crashing and fast tracking. Crashing reduces our project from 9 to 7 days by adding resources, increasing costs by $5,000. Fast tracking reduces it to 7.5 days by overlapping activities, with no direct cost increase but higher risk. A combined approach could potentially reduce the project to 6 days, but with both increased costs and significantly higher risks. Best practices include identifying the critical path before optimization, considering both techniques for flexibility, analyzing cost-benefit ratios for crashing, and carefully assessing dependency risks for fast tracking. The optimal approach depends on your project constraints - whether time, cost, or risk is your primary concern.