Question

The following information is provided for the tasks on a project. Times are in days. Task Time Predecessor A 12 B 21 B, C F 15 G 5 F, G H 17 [Select ] The critical path is [Select ] The time to complete this project will be The slack for task G is Select ] If the duration on task A increases by three days, how long will the project take to complete? I Select ]

Answer 1

CKDG в Possible path | Duration (days) Maximum A-C-D-G-H 12 + 8 + 6+ 5 + 17 = 48 No A-C-E-F-H 12 + 8 + 7 + 15 + 17 = 59 No B-E-F-H 21 + 7 + 15 + 17 = 60 Yes The critical path is the one which takes maximum duration to complete. Hence, B-E-F-H is the critical path Time to complete the project = 60 days Alternatively this can be calculated as shown below

NO I e R т 13 Task Time Early start Early finish Late start Late finish Slack 14 A 12 O =P14+014 1=S14-014 =R16 =S14-Q14 15 B 21 0 =P15+015 1=S15-015 =R18 =S15-Q15 16 C8 =Q14 =P16+016 =S16-016 =MIN(R17:R18) |=S16-Q16 17 D6 =Q16 =P17+017 =S17-017 =R20 =S17-Q17 18 E 17 =MAX(Q15:016) |=P18+018 1=S18-018 |=R19 =S18-Q18 19 F 15 =Q18 =P19+019 =S19-019 =R21 =S19-Q19 20 G5 =Q17 =P20+020 =S20-020 =R21 =S20-020 21 H 17 =MAX(Q19:Q20) =P21+021 =S21-021 =Q21 =S21-Q21 22

Note: 1. During forward pass if an activity is preceded by multiple activities, then the early start time for that activity will be considered of the activity whose early finish time will be maximum. 2. Similarly, during backward pass the minimum late finish time will be considered as the late start time for an activity if it succeeds multiple activities. 3. The cells highlighted in yellow are the activities having 0 slack and hence, critical activities.

Slack = Late finish - Early Finish

Na talk to care finish ate store Late finish|slack 13 N O P Q RS 13 Task | Time Early start Early finish Late start |Late finish Slack 14 A 12 O 12 1 15 B 21 0 21 0 21 16 C 2013 21 38 12 26 32 28 43 15 20 G 5 H17 43 31 60 28 38 43 12 43 60 43 0

Slack is 0 for activities B,F,E,H

Thus, critical path = B-E-F-H

Time to complete the project = Early finish of the activity H = 60 days

Slack for task G = 12 days

Project duration will increase by 2 days i.e. from 60 to 62 if the task A duration increases by 3 days.

Possible path	Duration (days)	Maximum
A-C-D-G-H	(12+3) + 8 + 6+ 5 + 17 = 51	No
A-C-E-F-H	(12+3) + 8 + 7 + 15 + 17 = 62	No
B-E-F-H	21 + 7 + 15 + 17 = 60	Yes