Scheduling

Things to learn... Precedence analysis Gantt Charts PERT / CPA

Why activity planning?? Activity Planning will help to: Ensure that the appropriate resources will be available precisely when required Produce a detailed schedule showing which staff carry out each activity Produce a detailed plan against which actual achievement may be measured Produce a timed forecast

Precedence analysis Decides what activities must be carried out before particular activity can start. Must be done before an activity plan can be produced.

Gantt Charts Developed by Henry Gantt, around 1917. Gantt charts are easy to use and produce. They are very useful for use on less complex projects. Commonly used due to there simplicity. Gantt charts are easily understood and easy to read.

Gantt Charts

Gantt Charts Draw the following Gantt chart Tasks Precedence Time a - 5 days b - 4 days c a 6 days d b 2 days e b 5 days f c,d 8 days Get students to draw the Gantt chart.

Gantt Charts

Network planning models PERT The Program Evaluation and Review Technique Developed by: US Navy with BOOZ-Allen Hamilton and Lockheed Corporation for the Mainly use for R&D projects

Network planning models CPM Critical Path Method Also known as CPA Critical Path Analysis Developed by DuPont Inc in the Late fifties early sixties(1958) to facilitate Developed for use in construction projects

Network planning models A simple on arrow network model 1 2 3 4 5 Start End a b c d e f g h

Terminology Activity Event A specific task, uses resources takes time to complete Event The result of completing an activity Events use no resources

Terminology Network - The combination of all activities and events define the project and the activity precedence relationships Path - The series of connected activities (or intermediate events) between any two events in a network Critical - Activities, events, or paths which, if delayed, will delay the completion of the project. A project’s critical path is understood to mean that sequence of critical activities that connect the project’s start event to its finish event

The framework of PERT and CPM For proceeding with PERT/CPM following common six points have to be followed: Define the project with significant activities or tasks Develop relationship among the activities Draw network connecting all activities Assign time and/or cost estimates to each activity Compute the critical path

The Language of PERT/CPM concluded An activity can be in any of these conditions: It may have a successor(s) but no predecessor(s) - starts a network It may have a predecessor(s) but no successor(s) - ends a network It may have both predecessor(s) and successor(s) - in the middle of a network

Building the Network AON Network AOA Network

Drawing Networks Activity-on-Arrow (AOA) networks use arrows to represent activities while nodes stand for events Activity-on-Node (AON) networks use nodes to represent activities with arrows to show precedence relationships The choice between AOA and AON representation is largely a matter of personal preference. AON is Often preferred by project managers

Network syntax AOA Time moves from left to right Nodes are numbered sequentially A network may not contain loops Precedents are the immediate preceding activities Dummy activities can be used to indicate a particular precedence

Network syntax Time moves from left to right Nodes are numbered sequentially 1 2 3 a b

Network syntax A network may not contain loops 1 2 3 4 This is not allowed a b c d

Network syntax Precedents are the immediate preceding activities 1 2 3 Design Build 4 Commission

Network syntax Dummy activities can be used to indicate a particular precedence 1 2 3 Wrong 4 Right a b c

A Sample Set of Project Activities and Precedences

Precedence Networks Precedence network also known as Activity on Node Becoming more common as it is used by many project planning software packages Often preferred by project managers

Precedence Networks Syntax the same as for On Arrow networks Except there are no dummy activities Precedence networks must start with a start node and end with a end node

Stage 1 of a Sample AON Network

Stage 2 of a Sample AON Network

A Completed Sample AON Network

Stage 1 of a Sample AOA Network

Stage 2 of a Sample AOA Network

A Completed Sample AOA Network

A Completed Sample AOA Network Showing the Use of a Dummy Task

On Arrow Networks Draw the following as an on arrow network Tasks Precedence Time a - 5 days b - 4 days c a 6 days d b 2 days e b 5 days f c,d 8 days

On Arrow Networks How to start ….. 1 2 3 start a b

On Arrow Networks What not to do 1 2 3 start a b 4 5 6 c d e

On Arrow Networks A better way …… 1 2 3 start a b c d e

On Arrow Networks It is then less confusing that c & d go to the same event … but what about e & f ? 1 2 3 start a b 4 5 6 c d e f

On Arrow Networks The completed on arrow network …. 1 2 3 start a b 4 5 c d e f end

On Arrow Networks Another on arrow network to draw Tasks Precedence Time a - 6 weeks b - 4 weeks c a 3 weeks d b 4 weeks e b 3 weeks f - 10 weeks g e,f 3 weeks h c,d 2 weeks

On Arrow Networks The network with activity times added 1 3 4 6 2 5 B=4 D=4 F=10 E=3 G=3 H=2

Precedence Networks Draw the following as an Precedence network Tasks Precedence Time a - 5 days b - 4 days c a 6 days d b 2 days e b 5 days f c,d 8 days

Activity list for the Project Activity Description Immediate Predecessors A R&D product design - B Plan market research - C Routing (manufacturing engineering) A D Build prototype model A E Prepare marketing brochure A F Cost estimates (industrial engineering) C G Preliminary product testing D H Market survey B, E I Pricing and forecast report H J Final report F, G, I

2 5 7 1 4 8 3 6 Routing (C) Product Design (A) Market Research Plan (B) Prototype (D) Marketing Brochure (E) Cost Estimates (F) Testing (G) Survey (H) Pricing and Forecast (I) Final Report (J) COMPLETION Activity list for the Project Activity Description Immediate Predecessors A R&D product design - B Plan market research - C Routing (manufacturing engineering) A D Build prototype model A E Prepare marketing brochure A F Cost estimates (industrial engineering) C G Preliminary product testing D H Market survey B, E I Pricing and forecast report H J Final report F, G, I

Exercise 1 Tasks Precedence Time a - 6 weeks b - 4 weeks c - 3 weeks d a 4 weeks e b 3 weeks f b 2 weeks g c 3 weeks h d,e 2 weeks i f 1 week j g,i 2 weeks

Exercise 2 Tasks Precedence Time a - 3 weeks b - 5 weeks c a 7 weeks d b 5 weeks e c, d 6 weeks f b 4 weeks g b 8 weeks h c, d 4 weeks i e, f 3 weeks

Exercise 3 Tasks Precedence Time a - 2 weeks b - 4 weeks c - 3 weeks d a 3 weeks e a 5 weeks f c 6 weeks g c 4 weeks h d 4 weeks i d 8 week j b, e, f, i 2 weeks k - 4 weeks l g, k 3 weeks

Exercise 4 Tasks Precedence Time a - 3 weeks b a 5 weeks c a 3 weeks d c 1 weeks e b 3 weeks f b, d 4 weeks g c 2 weeks h g, f 3 weeks i e, h 1 weeks

Exercise 5 Tasks Precedence Time a - 3 weeks b - 5 weeks c a 14 weeks d a 5 weeks e b 4 weeks f b 7 weeks g d, e 8 weeks h g, f 5 weeks

Exercise 6 Another on precedence network to draw Tasks Precedence Time a - 6 weeks b - 4 weeks c a 3 weeks d b 4 weeks e b 3 weeks f - 10 weeks g e,f 3 weeks h c,d 2 weeks