IT 9626: Project Management - Using Project Management Tools

This section details the use of Gantt charts and PERT charts as project management tools. These tools are essential for planning, scheduling, and monitoring projects effectively.

1. Gantt Charts

A Gantt chart is a visual representation of a project schedule. It displays tasks against a timeline, showing start and finish dates, durations, and dependencies. It's a simple and widely used tool for project planning.

1.1 Components of a Gantt Chart

• Tasks: Individual activities that need to be completed.
• Start Date: The date when a task begins.
• Duration: The estimated time required to complete a task.
• End Date: The date when a task is scheduled to finish.
• Dependencies: Relationships between tasks (e.g., Task B cannot start until Task A is finished).
• Milestones: Significant points in the project timeline.

1.2 Creating a Gantt Chart

1. List Tasks: Identify all the tasks required to complete the project.
2. Estimate Duration: Estimate the time needed for each task.
3. Define Dependencies: Determine the relationships between tasks.
4. Create the Chart: Use project management software (e.g., Microsoft Project, Asana, Trello, or even a spreadsheet) to create the chart. The horizontal axis represents time, and the vertical axis lists the tasks.
5. Update Regularly: As the project progresses, update the chart with actual start and finish dates and any changes to dependencies.

1.3 Example Gantt Chart (Text Representation)

The following is a simplified text-based representation of a Gantt chart. In practice, software provides a graphical representation.

Task	Start Date	Duration (Days)	End Date
Task A: Requirements Gathering	2024-01-01	5	2024-01-05
Task B: Design	2024-01-05	7	2024-01-12
Task C: Development	2024-01-12	10	2024-01-22
Task D: Testing	2024-01-22	5	2024-01-26
Task E: Deployment	2024-01-26	2	2024-01-28

Figure: Suggested diagram: A simple Gantt chart showing tasks, start dates, durations, and end dates. The chart would visually represent the timeline of the project.

2. PERT Charts

PERT (Program Evaluation and Review Technique) charts are used for project scheduling, especially when tasks have uncertain durations. Unlike Gantt charts which assume fixed durations, PERT charts use probabilistic estimates for task durations. They are particularly useful for projects with a high degree of risk.

2.1 Estimating Task Durations with PERT

PERT uses three estimates for each task duration:

• Optimistic Time (a): The shortest possible time to complete the task.
• Most Likely Time (m): The most realistic time to complete the task.
• Pessimistic Time (b): The longest possible time to complete the task.

The expected duration (te) of a task is calculated using the following formula:

$$te = \frac{a + 4m + b}{6}$$

2.2 Constructing a PERT Chart

1. Identify Tasks and Dependencies: Same as with Gantt charts.
2. Estimate Durations: Use the optimistic, most likely, and pessimistic estimates for each task.
3. Draw the Chart: PERT charts are represented as a network diagram. Tasks are represented as nodes, and dependencies are represented as arrows.
4. Calculate Expected Durations: Calculate the expected duration for each task using the PERT formula.
5. Determine the Critical Path: The critical path is the longest path through the network diagram. The duration of the critical path determines the minimum project completion time.

2.3 Example PERT Chart (Text Representation)

The following is a simplified text-based representation of a PERT chart. A graphical representation is typically used.

Figure: Suggested diagram: A PERT chart showing tasks, dependencies, and estimated durations. The chart would visually represent the project network and the critical path.

Task	Optimistic (a)	Most Likely (m)	Pessimistic (b)	Expected Duration (te)
Task A: Requirements Gathering	5	7	10	7.33
Task B: Design	7	9	12	9.00
Task C: Development	10	12	15	12.33
Task D: Testing	5	6	8	6.33
Task E: Deployment	2	3	4	3.00

Critical Path: Based on the estimated durations, the critical path is A -> B -> C -> D -> E, with an expected duration of 31.33 days.

3. Comparison of Gantt Charts and PERT Charts

| Feature | Gantt Chart | PERT Chart |

Feature	Gantt Chart	PERT Chart
Duration Estimation	Fixed durations	Probabilistic durations (a, m, b)
Complexity	Simpler to create and understand	More complex, especially for large projects
Usefulness	Suitable for projects with well-defined tasks and durations	Suitable for projects with uncertain durations and high risk

Both Gantt charts and PERT charts are valuable tools for project management. The choice of which to use depends on the specific characteristics of the project.