# Practical: Network Diagram (PERT/CPM) in Project Management
## 1. Introduction
Project management involves planning, scheduling, executing, and controlling activities to achieve specific goals within a defined time frame. Among the most powerful tools used in project scheduling are Network Diagrams, particularly PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method).
Network diagrams provide a visual representation of project activities and their dependencies. They help project managers understand the sequence of tasks, identify critical activities, estimate project duration, and manage resources efficiently.
This practical provides a comprehensive study of Network Diagrams, PERT, and CPM techniques, including theory, calculations, examples, and applications. It is designed especially for polytechnic students in Computer Science and related fields.
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## 2. Objectives of the Practical
* To understand the concept of Network Diagrams
* To learn PERT and CPM techniques
* To identify task dependencies
* To calculate project duration
* To determine critical path
* To apply concepts in real-world projects
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## 3. Definition of Network Diagram
A network diagram is a graphical representation of a project that shows the sequence of activities and their interdependencies. It helps in scheduling, planning, and controlling complex projects.
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## 4. Introduction to PERT
PERT (Program Evaluation and Review Technique) is a statistical tool used to analyze and represent the tasks involved in completing a project, especially when activity durations are uncertain.
### Features of PERT:
* Uses probabilistic time estimates
* Suitable for research and development projects
* Focuses on time management
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## 5. Introduction to CPM
CPM (Critical Path Method) is a deterministic technique used for project scheduling where activity durations are known.
### Features of CPM:
* Uses fixed time estimates
* Focuses on cost and time optimization
* Suitable for construction and production projects
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## 6. Differences between PERT and CPM
| Feature | PERT | CPM |
| -------------- | ------------- | ------------- |
| Nature | Probabilistic | Deterministic |
| Time Estimates | Three | One |
| Focus | Time | Cost & Time |
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## 7. Components of Network Diagram
### 7.1 Activities
Tasks required to complete the project.
### 7.2 Events (Nodes)
Starting and ending points of activities.
### 7.3 Arrows
Represent activities.
### 7.4 Dummy Activities
Used to show dependency without consuming time.
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## 8. Time Estimates in PERT
PERT uses three time estimates:
* Optimistic Time (To)
* Most Likely Time (Tm)
* Pessimistic Time (Tp)
### Expected Time Formula:
Te = (To + 4Tm + Tp) / 6
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## 9. Steps to Construct Network Diagram
1. Identify all activities
2. Determine sequence
3. Draw network diagram
4. Estimate time
5. Identify critical path
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## 10. Critical Path Method
The critical path is the longest path in the network diagram which determines the shortest completion time.
### Key Terms:
* Earliest Start Time (EST)
* Latest Start Time (LST)
* Float/Slack
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## 11. Forward Pass Calculation
Used to calculate earliest start and finish times.
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## 12. Backward Pass Calculation
Used to calculate latest start and finish times.
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## 13. Float Calculation
Float = LST - EST
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## 14. Sample Project Example
### Project: Software Development
Activities:
A: Requirement Analysis
B: Design
C: Coding
D: Testing
E: Deployment
(Include detailed calculations)
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## 15. Advantages of PERT/CPM
* Better planning
* Time management
* Resource optimization
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## 16. Limitations
* Complex for large projects
* Requires accurate data
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## 17. Applications
* Construction
* IT Projects
* Manufacturing
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## 18. Conclusion
Network diagrams (PERT/CPM) are essential tools in project management.
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## 19. Viva Questions
1. What is PERT?
2. What is CPM?
3. Define critical path.
