Managing Operations: Week 6

Precedence Table 

• Definition: 'A representation of ordering of elements which comprise total work content of product/service'.

Network Diagrams: Activity on Node convention (AoN)

• Project broken down separate activities , represented nodes (boxes) diagram.
• Flow activities left-right.
• Arrows indicate precedence - not time.
• Activities (nodes) identified label e.g. letters A-Z small project.

Start to End

If more 1 starting/ending activity, create new activity labelled Start/End 0 duration.

The Network and Paths

Network analysed number different paths from start end network.

The Critical Path

• Path through network greatest duration.
• Length whole project time complete path greatest total duration.
• Activities critical path must started + completed time, otherwise completion project delayed.

Non-critical activities + Float

• Activities which not critical path = non-critical.
• Float any activiity amount time by which duration could extended point where would become critical.

Calculating Early Start Time + Early Finish Time (Forward Pass)

• EST starting activity = 0
• Move forward through network (left-right)
• EFT activity = EST + Duration
• EST activities after starting activity set EFT preceding activity
• If 2/+ preceding activities, take highest EFT value 

1. FORWARD PASS (Left-right)

• Place numbers along top activity
• Add up durations
• Choose highest answer at junction

Calculating Late Start Time and Late Finish Time (Backward Pass)

• Move backward through network (right-left)
• LST activity = LFT - Duration
• LFT activities after starting activity set LST, following activity. 
• If 2/+ following activities, take lowest LST value.

2. Backward Pass (Right-left)

• Place numbers along bottom activity.
• Subtract durations.
• Choose lowest answer junction.