1. G048: Lecture 06 Critical Path Analysis Mr C Johnston ICT Teacher www.computechedu.co.uk

2. Session Objectives Understand the key requirements of critical path analysis (CPA) Understand the purpose, benefits and limitations of using such a tool Be able to apply the principles of CPA to a scenario.

3. Planning and Monitoring Tool

4. Critical Path Analysis May be used as part of the decision making process Enables a firm to plan and monitor operations Time related – identifies the maximum time for an operation to be completed Identify potential problems in implementing operation Identifies where and when resources (including human ones) are needed

5. Critical Path Analysis Advantages Maximise efficiency in the use of time Improve efficiency and generate cost saving in the use of resources Beneficial to monitoring cash flow Disadvantages Usefulness may be limited in complex and large scale operations Necessity of having clear and reliable information Skilled management and team philosophy is essential

6. The Process

7. CPA – The Process Identify and prioritise the activities Identify which activities MUST be done before others EST – identify earliest start time – work from left to right adding up timings LFT – identify latest finish time – work from right to left subtracting timings Identify the critical path – points connecting ESTs and LFTs (where these are the same) Identify the FLOAT – tasks which can be completed outside the critical path

8. Critical Path Analysis Nodes: Show the start and finish of a task 12 Node numbers showing order of activities in the left hand semi-circle of each node. 3 Earliest Start Time (EST) 5 Latest Finish Time (LFT) A 3 B 5 Arrows indicate the order of the tasks, the letter above shows the order, the time period below the arrow The Critical Path

9. Example 1 – Making Bread TaskDescriptionOrder / LogicTime AWeigh IngredientsComplete first1 (mins) BMix ingredientsAfter A3 (mins) CDough rising timeAfter B60 (mins) DPrepare tins1 (mins) EPre-heat oven10 (mins) FKnead dough and place in tinsAfter C and D2 (mins) G2 nd dough rising timeAfter F15 (mins) HCooking timeAfter E and G45 (mins)

10. Exercise #1: New Product Feedback TaskDescriptionOrder / LogicTime APlan Primary ResearchComplete first1 (wks) BPrepare Mail Shot (Postal Survey)After A3 (wks) CPrepare QuestionnaireAfter A2 (wks) DSend and Wait for RepliesAfter B3 (wks) EIssues QuestionnaireAfter C3 (wks) FCompile and Analyse RepliesAfter D and E2 (wks) GPlan selling campaignAfter D, E, F2 (wks) Draw a critical path analysis diagram for this scenario

11. Exercise #2: Swimming Pool Installation Draw a critical path analysis diagram for this scenario TaskOrder / LogicTime A-2 (wks) B-4 (wks) CAfter A3 (wks) DAfter A5 (wks) EAfter A1 (wks) FAfter C2 (wks) GAfter D5 (wks) HAfter B,E7 (wks) IAfter H2 (wks) JAfter F,G,I3 (wks)

12. Exercise #2: Swimming Pool Installation TaskOrder / LogicTime A-2 (wks) B-4 (wks) CAfter A3 (wks) DAfter A5 (wks) EAfter A1 (wks) FAfter C2 (wks) GAfter D5 (wks) HAfter B,E7 (wks) IAfter H2 (wks) JAfter F,G,I3 (wks) 8 16 3 5 11 5 4 4 2 2 2 1 0 0 7 13 6 11 4 7 8 A2A2 B4B4 E1E1 D5D5 C3C3 H7H7 F2F2 G5G5 I2I2 J3J3

13. Exercise #3: Large Turbine Installation Draw a critical path analysis diagram for this scenario TaskOrder / LogicTime A-6 (weeks) B-5 (weeks) C-4 (weeks) DA EB8 (weeks) FB,C8 (weeks) GD,E7 (weeks) HF4 (weeks) IH,G3 (weeks)

14. Exercise #3: Large Turbine Installation TaskOrder / LogicTime A-6 (weeks) B-5 (weeks) C-4 (weeks) DA EB8 (weeks) FB,C8 (weeks) GD,E7 (weeks) HF4 (weeks) IH,G3 (weeks) 3 5 5 5 13 16 2 6 9 1 0 0 7 23 6 20 4 13 A6A6 B5B5 E8E8 D4D4 H2H2 F8F8 G7G7 I3I3 C4C4

15. Exercise #4: Aircraft Maintenance TaskDescriptionOrder / LogicTime APosition & jack up aircraft. Clean undercarriage & remove wheels Complete first2 (days) BInspect engines2 (days) CInspect airframe4 (days) DInspect undercarriage2 (days) ERectify engines4 (days) FRectify airframe3 (days) GRectify undercarriage & refit wheels4 (days) HCheck rectification & sign off2 (days) Work out the order / logic and then draw a critical path analysis for this scenario

16. Exercise #4: Aircraft Maintenance TaskDescriptionOrder / LogicTime APosition & jack up aircraft. Clean undercarriage & remove wheelsComplete first2 (days) BInspect enginesAfter A2 (days) CInspect airframeAfter A4 (days) DInspect undercarriageAfter A2 (days) ERectify enginesAfter B4 (days) FRectify airframeAfter C3 (days) GRectify undercarriage & refit wheelsAfter D4 (days) HCheck rectification & sign offAfter E, F, G2 (days) 3 4 5 5 4 5 2 2 2 1 0 0 7 11 6 9 9 4 6 6 A2A2 B2B2 E4E4 D2D2 H2H2 F3F3 G4G4 C4C4