PROJECT MANAGEMENT TECHNIQUES

PROJECT MANAGEMENT TECHNIQUES NETWORK ANALYSIS, CPM and PERT Course: Industrial Management and Safety Course Code: 5001 Module: III Arun Kumar S L Lecturer in Mechanical Engineering

Project Management • Project: • A project usually lead to following questions: • A Project consists of jobs, tasks or functions and activities that are 1. What is the expected time of related to each other. completion of the project? • A project has a clear beginning and 2. How will the delay of an activity clear ending. affects the overall completion time of the project? • Project Management involves Planning, Scheduling and Controlling 3. How additional funds, if available the works involved in a project. should be spent to reduce the time of the activities? 4. What is the probability of completing the project by scheduled date? Arun Kumar S L Lecturer in Mechanical Engineering

Network Analysis • Network analysis is an important • Important Network Analysis Project Management Technique. Techniques are: • In Network Analysis, large projects are • Critical Path Method (C P M) broken down to individual activities • Programme Evaluation and Review and arranged in logical sequence. Technique (P E R T) • It helps in deciding the tasks that need to be performed simultaneously and those need to be performed sequentially. • Network Analysis helps in designing, planning, coordinating, controlling and decision making in order to complete the project economically and in least time. Arun Kumar S L Lecturer in Mechanical Engineering

Some Definitions • Concurrent Activity: • Activity/Operation/Task: It is defined • These are independent operations and do as any individual operation, which not have any pre-operations. utilizes resources and time and has an end and a beginning. • These can be started separately at the same time. • Pre-operation or Predecessor Activity: • In the diagram below A and B are • It is the operation which precede the concurrent activities. operation under consideration. A • Eg: Machine foundation is pre-operation of machine installation. B • Post Operation or Successor Activity: • It is the operation which will follow after the operation under consideration. • Eg: Machine installation is the post operation of machine foundation. Arun Kumar S L Lecturer in Mechanical Engineering

Some Definitions • Dummy Activity: • These are the activities that do not consume any time or resources. • It is introduced to: 1. Maintain a unique numbering system for different activities. 2. Keep the logical sequence of activities and their inter relationships correct. • Dummy activity is denoted by ------> (dotted arrow) Arun Kumar S L Lecturer in Mechanical Engineering

Event • Event: • It is a point in time signifying the completion of some activities and the beginning of new ones • It is usually represented by circle or any geometrical symbol in a network known as node or connector. • Event Types: • Merge Event: When two or more activities end in one node, it is called merge event. • Burst Event: When two or more activities start from one node, it is called burst event. • Successor Events: The event or events which follow another event are termed successor events to that event. • Immediate Successor Event: Event or events without intervention of any other is known as immediate successor events. • Predecessor Events: The event or events which occur before another event are called predecessor events. • Immediate Predecessor Event: The event which comes before another event without the intervention of any other is known as immediate predecessor event. Arun Kumar S L Lecturer in Mechanical Engineering

Network Systems • There are two main systems for drawing a network: 1. Activity on Arrow (A.O.A.) System: • In this system, the activities are represented by an ‘arrow’ and is represented on the top of the arrow. • Events are represented by circles or nodes at the beginning and at the end of the arrow. • Duration of the activity is mentioned on the top or bottom of the arrow. Arun Kumar S L Lecturer in Mechanical Engineering

Network Systems – Activity On Node (A.O.N) • In this system, the activities are represented by circles or nodes and arrows are used only to show the dependency relationship between the activities and nodes. • The duration of the activity is represented on the top of the circle. Arun Kumar S L Lecturer in Mechanical Engineering

Fulkerson’s Rule for Numbering • Fulkerson’s rule is used for numbering the events in a Network Diagram. • The Fulkerson’s Rule for numbering the events in a network diagram involves the following steps: 1. There will be a single initial event in the network diagram and number this initial event as ‘1’. 2. Neglect all the arrows emerging out of the initial event numbered one. This will lead to the one or more initial events. 3. Number these apparently produced initial events as 2, 3, 4, etc. 4. Again neglect all the arrows emerging from these numbered events. 5. Follow step 3. 6. Continue these steps till the last event (that has no emerging arrows) is numbered. Arun Kumar S L Lecturer in Mechanical Engineering

Network Diagram - Problem • Draw the network diagram for the given data: Activity Predecessor Activity A - B - C A D A E B F C G D,E Arun Kumar S L Lecturer in Mechanical Engineering

Network Diagram - Problem • Draw the network diagram for the given data. Activity Predecessor Time A Activity (Weeks) - 4 B-3 CA2 DA7 EB6 F C4 G D,E 2 Arun Kumar S L Lecturer in Mechanical Engineering

Critical Path Method (C P M) • It is a Network Analysis • Some of the terms associated Technique. with CPM are: • It is a deterministic model with • Earliest Finish Time well-known activity times based • Latest Finish Time upon past experience. • Slack (or Float) • Critical Activity • It is suitable for problems in • Critical Path industrial setting, plant maintenance, civil construction projects, etc. Arun Kumar S L Lecturer in Mechanical Engineering

Procedure for C P M Arun Kumar S L Lecturer in Mechanical Engineering

Earliest Finish Time (EFT): • It is the earliest possible time in which a particular operation can be completed. • EFT = EFT of pre-operation + Schedule time for operation under consideration. • When an operation has more than one pre-operation, then, EFT = Largest EFT of pre-operation + Schedule time for operation under consideration. • It is denoted by top right corner outside of the operation circle and enclosed in a rectangle. Arun Kumar S L Lecturer in Mechanical Engineering

Latest Finish Time (LFT) • Latest Finish Time (LFT) is the total time by which the operation must be completed, so that the schedule date for the completion of the project may not be delayed. • LFT of an operation = LFT of the post operation – Time required for the same post operation • For last operation, LFT = EFT • It may be represented in a triangle. Arun Kumar S L Lecturer in Mechanical Engineering

Slack (or Float), Critical Activities and Critical Path • Critical Activities: • Slack or Float: • These are those activities, which if consume • It is the difference between LFT and EFT. more than the estimated time, the project will • On critical path it is zero. be delayed. • Slack is with reference to an event and float is • A critical activity is marked either by a thick with respect to an activity. arrow or a double line. • It gives the range of time available at an event • Critical Path: for accomplishing an activity without delaying the project completing date. • A path along the network in which EFT = LFT, is known as critical path. • Critical path is formed by critical activities. • A critical path consumes more resources. • It is the longest path and consumes maximum resources. • A critical path has zero float. • A critical path reveals those activities which must be manipulated by some means or the other, if the scheduled completion dates are to be met. Arun Kumar S L Lecturer in Mechanical Engineering

C P M - Problem Network Diagram • A project with 6 activities is shown below. • Draw the network diagram, mark the critical path and find the project duration. Use AOA Activmityethod. Dependency Time (Days) A-4 BA6 CB5 DA4 ED3 F C,E 5 Arun Kumar S L Lecturer in Mechanical Engineering

C P M - Problem A project is given here in tabular form. Find: 1. Draw the project network. 2. Identify the critical path 3. Find the project duration. 4. What is slack at each activity? Activity Time (Days) 1-2 6 1-3 8 2-4 7 3-4 12 4-6 3 5-6 5 3-5 7 5-7 11 6-7 10 Arun Kumar S L Lecturer in Mechanical Engineering

Programme Evaluation and Review Technique (P E R T) • It is a Network Analysis Technique. • An event oriented approach. • A probabilistic model with uncertainty in activity duration. • It is suitable in defence project and Research and Development where activity times cannot be reliably predicted. Arun Kumar S L Lecturer in Mechanical Engineering

Programme Evaluation and Review Technique (P E R T) - Terms • Optimistic Time (to): • Expected Time (te) : • It is the shortest possible time in • This is the time considered for the which an activity can be completed if actual completion of the project. everything goes exceptionally well. • All the three time estimates are taken • Most Likely Time (tm): into account for calculating expected time. • It is the time in which the activity is normally expected to complete under • te = (1/6)to + (2/3)tm + (1/6) tp normal conditions. • Standard Deviation = ������������−������������ • Pessimistic Time (tp): • Variance ������ (������������−������������)������ • It is the time in which an activity will = take to complete in case of difficulty, ������ i.e., if most of the things go wrong. • It is the longest of all time estimates. Arun Kumar S L Lecturer in Mechanical Engineering

Procedure for PERT Arun Kumar S L Lecturer in Mechanical Engineering

Problem on PERT Solution: • A project is composed of 9 activities as given below: Act 1-2 1-6 2-3 2-4 3-5 4-5 6-7 5-8 7-8 . to 2 2 5 1 5 2 3 2 7 tm 5 5 11 4 11 5 9 2 13 tp 14 8 29 7 17 14 27 8 31 1. Draw the Network Diagram. 2. Identify the Critical Path. 3. Find the project duration. 4. Find the slack at each event. Arun Kumar S L Lecturer in Mechanical Engineering

Solution-Continuation Arun Kumar S L Lecturer in Mechanical Engineering

CPM versus PERT CPM PERT • An activity oriented system • An event oriented approach. • A deterministic model with well known • A probabilistic model with uncertainty in activity times based on past experience. activity duration. • The expected time is the actual time taken. • The use of dummy activity is not necessary. • Expected time is calculated from to, tm and tp. • It marks critical activities. • Dummy activities are required for • It is suitable for problems in industrial setting, representing the proper sequencing. plant maintenance, civil construction projects, etc. • It does not demarcate between critical and non – critical activities. • It is suitable in defence project and Research and Development where activity times cannot be reliably predicted. Arun Kumar S L Lecturer in Mechanical Engineering