Introduction
The project manager of a construction company has developed the following network diagram for her building construction project. After receiving the plans, the manager must coordinate a number of tasks. Key areas she want to focus on, is time and risk. “Planning is responsible for project Time Management. The Plan process selects a scheduling methodology, tool, sets the format and establishes criteria for developing and controlling the schedule of a project. Rules and approaches for scheduling process are defined by the scheduling methodology”. PMI (2008)
She uses the three-point technique “An analytical technique that uses three estimates to represent three scenarios (optimistic, most likely, and pessimistic)” PMI (2008) to estimate durations of each tasks.
She uses the following calculations methods.
Critical Path
As critical Path is the driver for project completion, must be analyzed. The way we identify critical path in the network diagram is by adding the duration of each task path Wysocki (2012), Addition of the total duration of the project task is the critical path. Formula used to calculate expected time (O + 4M + P) / 6 (Optimistic –Most likely –Pessimistic).
The critical path is A – C – F – H – J. The project will therefore take 39 weeks to complete. This is identified with the calculated durations in the table below.
Method to calculate earliest start and earliest finish
Forward pass method through the network diagram is used, below three steps are used to find out ES and EF 1- The ES of the first task in the project is set to one “first day of the start of project work”, Wysocki (2012). The EF of any task is its ES plus its duration minus one “the reason for subtracting 1 is the fact that task starts at the beginning of a time unit” Wysocki (2012), so ES = 1, and EF = 1 + 7 - 1 = 7 2- Then go to the next task in the path, take the EF of the