Project Management for Business Week 4 LSBM , Sept 2015 Project Management for Business

Outline Project Scheduling PERT/CPM

University of Nottingham 8/6/2018 Project Scheduling It is part of project management within the Planning phase of the Project Development Life Cycle. Project Scheduling: Allocate resources to execute all activities in the project. Maria Petridou

University of Nottingham 8/6/2018 Project Scheduling Objectives: Establish beginning, ending and duration of each activity in the project. Calculate overall completion time of the project given the amount of usually limited resources. Determine the critical path and its duration. Determine the slack time for all non-critical activities and the whole project. Maria Petridou

University of Nottingham 8/6/2018 Project Scheduling Phases: Define activities or tasks according to the project objectives. Identify precedence relationships or dependencies Estimate time required to complete each task. Draw an activity-on-arrow / activity-on-node PERT diagram. Apply CPM to calculate earliest and latest starting times, earliest and latest completion times, slack times, critical path etc. Construct a GANTT chart. Reallocate resources and resolve if necessary. Continuously monitor/revise the time estimates along the project duration. Maria Petridou

University of Nottingham 8/6/2018 PERT Diagrams Program Evaluation and Review Technique It is a network model that shows activity completion times and their precedence. Tool used to control the length of projects. PERT was developed in the late 1950’s for the US Navy. It has the potential to reduce both the time and cost required to complete a project. Maria Petridou

University of Nottingham 8/6/2018 PERT Diagrams 3 B D A F 1 2 5 6 C E 4 Single start node Single finish node Maria Petridou

University of Nottingham 8/6/2018 PERT Diagrams Activity-on-node Activity-on-arrow Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method ET – Earliest node time for given activity duration and precedence relationships LT – Latest node time assuming no delays ES – Activity earliest start time LS – Activity latest start time EF – Activity earliest finishing time LF – Activity latest finishing time Slack Time – Maximum activity delay time Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 A ( 3 ) D ( 5 ) 1 5 B ( 4 ) E ( 2 ) 3 4 C ( 7 ) Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method Step 1. Calculate ET for each node. For each node i for which predecessors j are labelled with ET(j), ET(i) is given by: ET(i)= maxj [ET(j)+ t(j,i)] where t(j,i) is the duration of task between nodes (j,i). Step 2. Calculate LT for each node. For each node i for which successors j are labelled with LT(j), LT(i) is given by: LT(i)= minj [LT(j) – t(i,j)] where t(j,i) is the duration of task between nodes (i,j). Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 A ( 3 ) D ( 5 ) 1 5 B ( 4 ) E ( 2 ) 3 4 C ( 7 ) Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 A ( 3 ) D ( 5 ) 1 5 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 A ( 3 ) D ( 5 ) 1 5 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 13 A ( 3 ) D ( 5 ) 1 5 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 15 Maria Petridou 15

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 13 A ( 3 ) D ( 5 ) 8 1 5 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 16 Maria Petridou 16

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 13 max A ( 3 ) 8 D ( 5 ) 1 5 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 17 Maria Petridou 17

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 A ( 3 ) D ( 5 ) 1 5 13 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 C ( 7 ) 11 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 4 C ( 7 ) 11 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 5 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 4 C ( 7 ) 11 11 23 Maria Petridou 23

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 5 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 4 C ( 7 ) 11 11 24 Maria Petridou 24

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 5 min A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 4 C ( 7 ) 11 11 25 Maria Petridou 25

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 4 C ( 7 ) 11 11 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 Step 3. Calculate processing times for each activity. CPM – Critical Path Method Task Duration ES EF LS LF Slack Critical Task A 3 5 8 No B 4 Yes C 7 11 D 13 E 2 Maria Petridou

CPM – Critical Path Method University of Nottingham 8/6/2018 CPM – Critical Path Method 2 3 8 A ( 3 ) D ( 5 ) 1 5 13 13 B ( 4 ) E ( 2 ) 3 4 4 4 C ( 7 ) 11 11 Maria Petridou

Project Management Example: General Foundry Inc. Have 16 weeks to install a complex air filter system on its smokestack May be forced to close if not completed w/in 16 weeks due to environmental regulations Have identified 8 activities

AON Network for General Foundry

Activity Time Estimates

Determining the Project Schedule Some activities can be done simultaneously so project duration should be less than 25 weeks Critical path analysis is used to determine project duration The critical path is the longest path through the network

Critical Path Analysis Need to find the following for each activity: Earliest Start Time (EST) Earliest Finish Time (EFT) Latest start time (LST) Latest Finish Time (LFT)

Forward Pass If only 1 immediate predecessor, then Identifies earliest times (EST and EFT) EST Rule: All immediate predecessors must be done before an activity can begin If only 1 immediate predecessor, then EST = EFT of predecessor If >1 immediate predecessors, then EST = Max {all predecessor EFT’s}

EFT Rule: EFT = EST + activity time Node Notation:

Forward Pass: Earliest Start and Finish Times

Backward Pass Identifies latest times (LST and LFT) LFT Rule: If activity is the immediate predecessor to only 1 activity, then LFT = LST of immediate follower If activity is the immediate predeccor to multiple activities, then LFT = Min {LST of all imm. followers}

LST Rule: LST = LFT – activity time

Backward Pass: Latest Start and Finish Times

Slack Time and Critical Path(s) Slack is the length of time an activity can be delayed without delaying the project Slack = LST – EST Activities with 0 slack are Critical Activities The Critical Path is a continuous path through the network from start to finish that include only critical activities

Project Schedule and Slack Times

Critical Path and Slack Times

Project Scheduling Questions?

Reference List 1. Project Management: Achieving competitive advantage, chapter 9 2. Project Management: A managerial Approach, chapter 13, Project Termination