Question

1. What are the strengths and weaknesses of using a Gantt chart for representing a project plan? How about a Network diagram and a PERT diagram? When they should be used ? Is one method “better” than the other? Should we combine them together?

Please No handwritten work.

Answer 1

Strengths of using Gantt chart for representing a project plan:

1. The main advantage of using Gantt chart is its simplicity. It is very simple to create and understand.
2. You can effectively communicate the content in a Gantt chart to anyone without training him how to understand it. This is possible because it is simple to understand and it does not require any complex project knowledge.
3. All the tasks, sub-tasks and mile-stones can be easily represented
4. We can have a look at our plans by day, week or month etc.which will give us a broader view of our timelines.
5. Help us to understand the resource requirements easily.
6. Dates and timelines are clearly visible which prevents confusion and miscalculation. This helps in sticking to the schedule planned.
7. We can see completed, pending and on-going tasks are clearly visible in stacked bars.

Weaknesses of using Gantt chart for representing a project plan:

1. The first and most important weakness of a Gantt chart is looking at dependencies of the tasks. There is no clear connection to identify the connections of task with its dependencies.
2. When the number of activities increases, it becomes more complex and difficult to understand the dependencies.
3. There is no way to find out how a delay in one task effects the entire project timeline. This is a major drawback.
4. Changing contents in a Gantt chart is a time consuming process

Network Diagram and PERT diagram:

• They give us clear connection between the tasks using arrows. This helps us understand the dependencies between tasks( activities) using the direction it is pointed to.
• We do calculation of mean time for a task using optimistic, most likely and pessimistic times which gives us an advantage if there are any delays in tasks.
• "Earliest start" and "Latest finish" times of every task are calculated which gives us clear picture of when our task can be started and finished.

Which is better and when they should be used?

Considering my above explanation the following should be analyzed carefully before using

• Gatt chart : This can be used if the tasks does not deviate more during a project execution. More suitable for stable projects. Showing tasks completion, pending or in-progress statuses is very easy. So it will be very helpful to display project statistics to higher authorities who do not require higher information of all the sub-tasks. This can be used to clearly communicate individual tasks.
• PERT diagram: This can be used for complex projects with deviating task timelines. This can be used if you want to anticipate the project completion time. This can be used to determine critical path to meet deadlines.

Which method is better entirely depends on the requirements, complexity, time estimation and stability of the project. You can consider the above information to decide which one is better.