You are a contractor that has been asked to build an apartment complex. The associated AON Network diagram and the Time/Cost table are provided below. (Based on the table, you could crash activity B for one week only at a cost of $250 or two weeks for $500.) The owner wants the apartment complex built in 29 weeks. The owner will charge a penalty cost of $1500 per week if the complex is not completed on time. A-8 -5 F-4 E -8 H - 4 -5 D- 6 G -6 Normal Time Minimum Time Crash Cost Activity per Week A 8 7 200 5 250 5 1750 6 5 500 E 8 1500 F 4 3 1200 G 6 1000 H 4 2 2000 PART 1- CRITICAL PATHS Find the duration of each of the possible paths. ACEFH - ADEFH - ACEGH - ADEGH - BDEFH - BDEGH - 1. What is the Critical Path? What is the duration of this project presently? 2. What would be the penalty associated for the project in the current state? PART 2 - SLACK TIMES 3. Which activities currently have slack? In other words, which activities are NOT presently on the Critical Path? ABCDEFGH Prep for 4 and 5: What is the longest path (in terms of time) for ONLY those items with slack? For Example: Suppose C's longest path was ACEFG at 45 day (Not true, of course) you would write C- ACEFG 4. What is the actual slack time for activity F? 5. What is the actual slack time for activity A? Hint for 4 and 5: What is the difference between each of the paths listed in question E and the critical path? (This tells you how long each activity listed in question can be delayed without affecting the Total Project Time with the present Critical Path.) If the item is on the Critical path it will have 0 slack. CRASH FIRST ITEM Crash the project by 1 week by altering the activity that will save us the most money. 6. Which activity will you crash first? Make the necessary change to your network diagram. ADEFH - ACEFH - ACEGH - ADEGH - BDEFH - BDEGH - 7 What is the resulting critical path (or paths) and also the new project duration? 8. How much money did you save (net savings) by crashing this activity? Net Savings = 1 Week Penalty Saved - 1 Week Crash Cost CRASH SECOND ITEM Again, crash the project by 1 week by altering the activity that will save us the most money. 19 Which activity will you crash second? Make the necessary change to your network diagram. ACEGH - ACEFH - ADEFH - ADEGH - BDEFH - BDEGH - 10. What is the resulting critical path (or paths) and also the new project duration? 11. How much money did you save (net savings) by crashing this activity? Net Savings = 1 Week Penalty Saved - 1 Week Crash Cost CRASH THIRD ITEM Crash the project by 1 week by altering the activity that wll save us the most money. This will get us to the desired completion date that will eliminate the penalties. 12. Which activity will you crash third? Make the necessary change to your network diagram. ADEFH - ACEFH - ACEGH - ADEGH - BDEFH - BDEGH - 13. What is the resulting critical path (or paths) and also the new project duration? 14. How much money did you save (net savings) by crashing this activity? Net Savings = 1 Week Penalty Saved - 1 Week Crash Cost TOTAL SAVINGS 15. How much did you save, in total by crashing the system down to 29 weeks?