0]= 55-3]= 2

Hence the critical activities (those with a float of zero) are 1,3,5,6,7,9 and 11. This means that there are two critical paths, namely 1-11-5-7-9 and 1-3-6-7-9. Thus, the engineering firm finds the following:

• activity eight "Modify Distribution System" is not critical, therefore cutting its completion time has no effect upon the overall project completion time or on the critical paths

• activity four "Order Parts for Modified Distribution System" has a float time of 2 weeks so increasing its completion time by 2 weeks does not affect the overall project completion time. However activity four will then become critical so the critical paths will be affected.