In: Operations Management
4). Eight maintenance activities, their normal durations in weeks, and the crew sizes for the normal condition are as follows:
| 
 Activity  | 
 Duration in Weeks  | 
 Crew size  | 
| 
 AC  | 
 6  | 
 8  | 
| 
 BC  | 
 6  | 
 7  | 
| 
 BE  | 
 2  | 
 6  | 
| 
 CD  | 
 3  | 
 2  | 
| 
 CE  | 
 4  | 
 1  | 
| 
 DF  | 
 7  | 
 4  | 
| 
 EF  | 
 4  | 
 6  | 
| 
 FG  | 
 5  | 
 10  | 
| 
 Extra Crew  | 
 Weeks Saved  | 
 Crash cost per week  | 
| 
 1  | 
 1  | 
 $100  | 
| 
 2  | 
 2  | 
 $120  | 
| 
 3  | 
 2  | 
 $200  | 
| 
 4  | 
 3  | 
 $250  | 
If there is a penalty cost of $1,250 per week beyond the minimum maintenance time of 20 weeks, recommend the minimum cost schedule.
| 
 Activity  | 
 Optimistic  | 
 Most Likely  | 
 Pessimistic  | 
| 
 AC  | 
 5  | 
 6  | 
 8  | 
| 
 BC  | 
 4  | 
 6  | 
 10  | 
| 
 BE  | 
 2  | 
 2  | 
 2  | 
| 
 CD  | 
 2  | 
 3  | 
 7  | 
| 
 CE  | 
 2  | 
 4  | 
 9  | 
| 
 DF  | 
 5  | 
 7  | 
 13  | 
| 
 EF  | 
 3  | 
 4  | 
 6  | 
| 
 FG  | 
 4  | 
 5  | 
 16  |