# Book Report Essay

687 Words3 Pages
1. Provide the definitions of critical path and critical chain. How do they differ?

Critical path and critical chain are both schedule network analysis techniques.

Critical path is the one that determines the shortest time to complete a project, which assumes low uncertainty and does not consider resource dependencies.

Critical chain is a modified or refined technique about critical path; it involves the deterministic and probabilistic approaches to analyze the project schedule, which is more realistic and practical than critical path.

Differences between critical path and critical chain:
 Critical path is based on deterministic task duration, while critical chain involves the deterministic and probabilistic approaches;
This buffers help reduce the risk of non-critical tasks. They are located at the end of each non-critical task.
3. Describe common practices to estimate the duration of project activities as well as real reasons that cause project delays.

Common practices to estimate the duration of project activities:

 Down to Top: When asked about the time it takes to complete a task or activity in a whole project, each owner of the activity tends to add his safety time to the reported number; therefore, the project manager collects all the numbers from each owner and then adds his safety time to the overall duration of the project, say, the total time to complete the project. The finalized total time is more exaggerated.

 Top to Down: When given the total time by project manager, higher level managers tend to squeeze the time to reduce the time and cost. Therefore, lower level manager has to give up the initial schedule to satisfy higher level managers. The finalized time depends on the complexity of the organization: the more layers, the less time to complete a project.

Real reasons that causes project delays:

 Resource constraint: If a resource is shared by many projects or activities, it would be used in order of priority, thus leading to delay of activity or project with lower priority.

 Dependency: If two activities are serial relationship, which means one relies on the completion of