Use forward and backward pass to determine project duration and critical path

Summary

This video guides viewers through determining the project duration and critical path using a dependency table. It begins with a rough draft of activities and their dependencies, then refines the diagram with clear nodes for each activity, including early and late start and finish times. A forward pass calculates the early start and finish dates, while a backward pass identifies the late start and finish dates. The critical path is determined by identifying activities where early and late finishes align, emphasizing their importance in project management and introducing concepts of float and slack.

Takeaways

• 😀 Understanding the project duration and critical path is essential for effective project management.
• ✏️ Start by creating a rough draft of project activities based on their dependencies to visualize task relationships.
• 📅 Activity A is the first task, as it has no predecessors, followed by activities B and C, which depend on A.
• 🔄 The forward pass method is used to calculate early start and early finish times for all activities.
• ⏳ The total project duration is determined through the early finish of the last activity, which in this case is 19 days.
• 🔙 The backward pass method calculates late finish and late start times, helping to identify the flexibility of scheduling.
• 📊 The critical path is identified by finding activities where early finish and late finish times are the same.
• 🚦 Activities on the critical path (A, B, D, G, H) must be monitored closely, as any delays will extend the project duration.
• 🕒 Activities with slack time (C, E, F) can be delayed without affecting the overall project deadline, providing scheduling flexibility.
• 📈 The concepts of total float and free float are crucial for understanding how much leeway there is in project scheduling.

Q & A

What is the main objective of the video?

The main objective of the video is to determine the project duration and critical path based on a given table of dependencies.

How is the initial project activity identified?

The initial project activity, labeled as activity A, is identified as it has no predecessor.

What is the significance of activities B and C in relation to activity A?

Activities B and C depend on activity A, meaning they cannot start until activity A is completed.

How are early start and early finish calculated in the forward pass?

Early start is calculated by taking the early finish of the preceding activity, and early finish is determined by adding the activity's duration to its early start.

What process is used to find the late start and late finish of activities?

A backward pass is performed, subtracting the activity's duration from the late finish to determine the late start.

What is the importance of determining the critical path?

The critical path identifies the sequence of activities that directly impact the project's completion time; any delay in these activities will increase the overall project duration.

Which activities are identified as part of the critical path in the video?

The activities identified as part of the critical path are A, B, D, G, and H.

What is meant by 'float' or 'slack' in project management?

Float or slack refers to the amount of time that an activity can be delayed without affecting the overall project completion date.

Can you provide an example of an activity that has float?

Activity E is an example; it can be delayed by one day without impacting the project's end date because it has a late start and finish that allow for this flexibility.

What will happen if any activity on the critical path is delayed?

If any activity on the critical path is delayed, it will result in an increase in the entire project duration.