Operations management

Table of Contents

1. Topic pack - Operations management - introduction
2. Operations Management (OM) - Introduction
3. 5.1 Production methods notes
4. 5.1 Production methods - questions
5. 5.2 Costs and revenues - notes
6. 5.2 Costs and revenues - questions
7. 5.3 Break-even analysis - notes
8. 5.3 Break-even analysis - questions
9. 5.3 Break-even analysis - simulations and activities
10. 5.4 Quality assurance - notes
11. 5.4 Quality assurance - questions and activities
12. 5.5 Location - notes
13. Innovation - notes (HL only)
14. 5.6 Innovation - questions
15. 5.7 Production planning - notes
16. 5.7 Production planning - questions
17. 5.8 Project management - notes (HL only)
    1. Project management - introduction
    2. Critical path analysis
    3. Critical path analysis - The rules and methodology
    4. CPA Stage 1 The data collection
    5. CPA Stage 2 The draft network diagram
    6. CPA Stage 3 - tidying and simplifying
    7. CPA Stage 4 - Earliest starting time (EST)
    8. CPA Stage 5 - Add the Latest finishing time (LFT)
    9. CPA Stage 6 - Identify the CRITICAL PATH
    10. Use of networks
    11. Float analysis
    12. Evaluation of networks
    13. Example - A simple project network
    14. Use of CPA diagrams
18. 5.8 Project management - questions (HL only)
19. Print View

CPA Stage 6 - Identify the CRITICAL PATH

Critical activities are ones that have no free time - they must start and finish when they are planned. There cannot be delays on these activities or the entire project will be late. The critical path is the chain of critical activities which will be found winding its way through the network.

There is a three-point test to see if an activity is critical.

Test 1 - the earliest and latest start times are the same,
Test 2 - the earliest and latest finish times are the same,
Test 3 - start time + duration = finish time (there is no float).

Only if all three tests are met will the activity be critical. Beware of the activity that passes tests 1 and 2 but fails test 3.

Mark the path in some way on the diagram. In figure 8 below, we have marked the path with a series of double lines to make it very clear. In your diagram you only need to mark critical activities with a single set of double lines

Figure 8 Completed network diagram with critical path

Figure 9 gives a reminder of the key to the diagram. If asked to draw one, it is always worth providing a key as well.

Key:

Figure 9 Network diagram key

Stage 7 - CHECK IT

So, we now have a plan for our project and know that it should take 18 weeks, and that the critical activities, in time order are C, H and I.