Pom Lecture (26)

Unit 2 Management of Conversion System Chapter 9: Project Scheduling Lesson 26 - PROJECT MANAGEMENT Learning Objectives After reading this lesson you will be able to understand Identify the three major activities associated with successful project processes Diagram the network of interrelated activities in a project

Good Morning students, today we are going to introduce the concept of what is known as PROJECT MANAGEMENT. We would learn to appreciate the importance of the concept as applicable in Production and operations systems. What is project? An interrelated set of activities that have a definite starting and ending point and that result in a unique outcome for a specific allocation of resources. Let us consider an example to make it clear. In the production department of college book division of a big printing press the products are books, complicated books, books headed for the college market. Each book is a "project" that appears on the production editor's desk as a large pile of manuscript pages: a combination of typed copy, "tear sheet" copy of art and text from previous - editions, figures drafted by the author, and other illustrations. These disparate elements are sent off in different directions for various treatments and must appear bound within covers and ready for sale approximately ten months later. Successful projects begin with a clear definition of scope, objectives, and tasks. Planning for the production of a college text involves decisions about the book's specifications (size, color, paper, covers); design (typefaces, art); permissions (where and in what languages the book will sell); composition (setting the type); printing, and binding. Scheduling-involves overlapping time frames so that some tasks can be done at the same time (editing and establishing costs, for example), while other tasks that depend on prior events occur later (paging and indexing, for example); and the schedule must end at a time advantageous to sales. Planning and scheduling for a

specific book take place at a launch meeting, where activities are identified, the sequencing is established, and a time is set for each activity within the overall tenmonth limit. The book's advance through the schedule is recorded and adjustments made as necessary. The production editor of a press is able to carry a considerable number of books at the same time, very efficiently, thanks to the production schedule. There are three important activities in the initial phase of managing projects – selecting the project manager and team, defining scope and objectives, and planning the format for meetings and communication. Selecting the project manager and team Project managers should be good motivators, teachers, and communicators. They should be able to organize a set of disparate activities and work with personnel from a variety of disciplines. These qualities are important because project managers have the responsibility to see that their projects are completed successfully. Defining the scope and objectives A thorough statement of project scope, time frame, and allocated resources is essential to managing the project process. The scope captures the essence of the desired project outcomes in the form of major deliverables, which are concrete outcomes of the project process. These deliverables become the focus of management attention during the life of the project. Planning the project format A key activity for any project process is making decisions. The managers of successful project processes specify the format for how the team will make decisions and who will make them. Such a format sets down guidelines for meetings, for resolving issues, and for communication among team members. . Now that we have understood the meaning of a project, we shall turn our attention to what is known as:PROJECT PLANNING AND SCHEDULING Project planning Once the project has been defined and the project process organized, the team must formulate a plan that identifies the specific tasks to be accomplished and a schedule for their completion. Planning projects involves five steps: 1. defining the work breakdown structure 2. diagramming the network 3. developing the schedule 4. analyzing cost-time trade-offs, and 5. assessing risks. The work breakdown structure (WBS) is a statement of all work that has to be completed. The project manager must work closely with the team to identify all work tasks. An

activity is the smallest unit of wok effort consuming both time and resources that the project manager can schedule and control. Project scheduling In contrast to project planning, project scheduling is more specific. Scheduling establishes times and sequences of the various phases of the project. In project scheduling, the manager considers the many activities of an overall project and the tasks that must be accomplished and relates them coherently to one another and to the calendar. Now we shall we go into the details of project scheduling models. PROJECT SCHEDULING MODELS There are various methods for scheduling projects. In this section we look at two simple project scheduling models-Gantt charting and the Program Evaluation and Review Technique (PERT). Both are schematic models, but PERT also has some mathematical model adaptations. Let’s start with:GANTT CHARTS A Gantt chart is a bar chart shows the relationship of activities over time. Following table gives the symbols often used in a Gantt chart. An open bracket indicates the scheduled start of the activity, and a closing bracket indicates the scheduled completion. A heavy line indicates the currently completed portion of the activity. A caret at the top of the chart indicates current time. Gantt chart symbols Symbol

Meaning

(

Start of an activity

]

End of an activity

H

Actual progress of the activity

v

Point in time where the project is now

NETWORK MODELING It allows us to address project scheduling a little more formally than we can with the Gantt chart. Although network models are based on rigorous theory and precise definitions, we discuss only a few terms and concepts here. The following figure illustrates the essential features of network modeling. Each activity

is symbolized by an arc, an arrowed line segment (or, simply, an arrow). Both the beginning and the ending of each activity are symbolized by a node, a circle at the beginning or ending of the arrow. Joint nodes represent the precedence relationships of the activities: An arc whose ending node is the beginning node of a second arc represents an activity that must precede the second activity. In the following figure there are six nodes, numbered 1-6. The arcs are named by their beginning and ending nodes:arc 1-2, 1-3, 2-4, 2-5, 4-6, and 5-6. The lengths of the arcs are of no significance. Nodes may be lettered, rather than numbered, or arcs as well as nodes may be numbered or lettered. Since arc 1-3 in the figure ends at the node that begins arc 3-6, arc 1-3 represents an activity that must precede activity 3-6. In talking about networks, we may refer to arc 1-2, for example, interchangeably with activity 1-2. Well my friends, all of you must have a fair bit of an idea of PROGRAM EVALUATION AND REVIEW TECHNIQUE (PERT), that you might have covered under quantitative techniques or operations research papers during the earlier semesters. However I would be failing in my duty if I do not take it up again during the current discussion. Indeed such is importance of this technique that universally almost all projects are evaluated on the basis of this method. Here we go. NETWORK MODELING Network modeling allows us to address project scheduling a little more formally than we can with the Gantt chart. Although network models are based on rigorous theory and precise definitions, we discuss only a few terms and concepts here. PROGRAM EVALUATION AND REVIEW TECHNIQUE (PERT) Development of PERT In 1958 the U.S. Navy developed Program Evaluation and Review Technique (PERT) for planning and control of the Polaris nuclear submarine project. The results of using PERT in that application, in which some 3,000 contractors were involved, is generally reported to have reduced by two years the project completion time for the Polaris project. In both government and industry today, PERT is still widely used.

2

4

5 6 1

3

Figure 26.1 Network of nodes and arcs The Figure 26.1 illustrates the essential features of network modeling. Each activity is symbolized by an arc, an arrowed line segment (or, simply, an arrow). Both the beginning and the ending of each activity are symbolized by a node, a circle at the beginning or ending of the arrow. Joint nodes represent the precedence relationships of the activities: An arc whose ending node is the beginning node of a second arc represents an activity that must precede the second activity. In the Figure 26.1 there are six nodes, numbered 1-6. The arcs are named by their beginning and ending nodes: arc 1-2, 1-3,2-4,2-5,4-6, and 5-6. The lengths of the arcs are of no significance. Nodes may be lettered, rather than numbered, or arcs as well as nodes may be numbered or lettered. Since arc 1-3 in the figure ends at the node that begins arc 3-6, arc 1-3 represents an activity that must precede activity 3-6. In talking about networks, we may refer to arc 1-2, for example, interchangeably with activity 1-2. A similar modeling approach called the Critical Path Method (CPM) is also used by business and government, Since CPM and PERT are nearly equivalent, we will concentrate only on PERT. Application of PERT First we should clarify the conditions under which PERT may be appropriately used. If your situation lacks the following features, PERT wiII yield little benefit. First the project must be one whose activities clearly are distinct and separable. Second, the project and activities must all have clear starting and ending dates. Third, the project must not- be complicated by too many interrelated tasks. Fourth, the project must be one whose activities afford alternative sequencing and timing. Language of PERT

The PERT language comprises simple symbols and terms. Key symbols are given for activity, dummy activity, event, and critical path of the network. Since the critical path requires the longest time through the network, management should watch it most closely to avoid unnecessary project delays. Logic of PERT A logical question to ask at this point in our discussions would be:How does PERT work? Well friends, It works by following these steps: 1. Clearly identify all activities in the project. 2. Identify the precedence requirements of the activities. 3. Diagram the precedence requirements as a sequence of activities. 4. Estimate the time each activity will take. 5. Calculate the critical path and other project performance criteria, creating the schedule and plan for subsequent control. 6. Reevaluate and revise as experience dictates. Time estimates are obtained from either past data or from people experienced in a particular activity. Optimistic to, pessimistic tp, and most likely tm times must be estimated so that the expected (average) time te can be calculated from the following equation.

(to + 4tm + tp)

te =

6 let me provide you with a (PERT) glossary.

Program Evaluation and Review Technique (PERT) glossary Symbol

Name

Meaning

Activity

Dummy Activity

Event

The beginning or ending of an activity. A point in time. Each project has a distinct project beginning and project ending. Designated as a node.

Network

The sequence of all project activities. The sequence obeys precedence requirements. Nodes connected by arcs.

Path

Anyone unique portion of the project sequence, beginning with the first activity and ending with the last activity, for which each activity has a single immediate successor. Each node pair has a single arc, an activity.

Critical path

Time Notation to

A task within the project that has a definite beginning and ending date or point in time. The activity consumes time. The length of the arrow is of no significance. Designated as an arc. A fictitious activity consuming no time; necessary to preserve the unique identification of activities.

The path whose activities are expected to consume the most time.

Interpretation

Calculation

Optimistic time: The least Assigned according to amount of time an activity experience or past data. is expected to consume, possible only under extremely favorable conditions. Very little chance, say 1 in 100.

tp

Pessimistic time: The greatest Assigned according amount of time an activity is to experience or past expected to consume, possible data. only under extremely unfavorable conditions. Very little chance, say 1 in 100.

tm

Most likely time: The single best Assigned according guess for activity completion time. to experience or past The mode activity time. data.

te

Expected time: The amount o time an activity is expected to consume, as likely to be exceeded as beaten. The mean activity time.

(to + 4tm + tp) t e= 6

Tp

Path time: The amount of time expected to be consumed by activities on a path.

T p= Σ t e for all activities on a path

TB

Expected beginning time: The amount of time expected to be consumed before an activity can begin. The sum of expected times for activities preceding a node on a path.

T B= t e for all activities on a path

TE

Earliest beginning time: The T E= max T B minimum amount of time that must be consumed before an activity can begin. The maximum expected beginning time.

TC

Expected completion time: The amount of time expected to be consumed once an activity begins.

T C= Σ t e for all succeeding activities

The sum of expected times for activities succeeding a node on a path. TL

Latest beginning time: The maximum T L =time allowed – max T C Amount of time that can be consumed before an activity begins, if the project is to be completed on time. The difference of the total time allowed for the project and the maximum expected completion time.

TS

Slack time: The amount of leeway time an activity can consume and still allow the project to be completed on time. The difference of the latest beginning time and the expected beginning time.

T S=T L– T E

Sample PERT network Net Work A

C

Meaning D

Represents activities AC, BC, and CD. CD may not begin until both AC and BC are completed. AC and activities.

B A

B

C

BD may not begin until AB is completed. CD 3 may not begin until AC is completed.

D B A

AB-BD and AC-CD are parallel pat/IS. However, AC does not have to begin at the same instant that AB begins, although it may. Similarly, BD does not have to be completed at the same instant that CD is completed, although it may. Similarly, BD may be completed before AC is completed.

D C

A

B o C

D

BC is a dummy activity, used when necessary to preserve the required sequence of the network. It may be symbolized in two ways, as shown. A dummy activity consumes no time. Using a dummy allows all activities to be identified by a unique pair of nodes. Activity CD cannot begin until activities AB and AC are completed. This network has two paths: AB-BCCD and AC-CD.

Diagramming the project as a network requires establishing the precedence relationships between activities. A precedence relationship determines a sequence for undertaking activities; it specifies that one activity cannot start until a preceding activity has been completed. Two different approaches may be used to create a network diagram. The first approach, the activity-on-arc (AOA) network, uses arcs to represent activities and nodes to represent events. An event is the point at which one or more activities are to be completed and one or more other activities are to begin. An event consumes neither time nor resources. Because the AOA approach emphasizes activity connection points, we say that it is event oriented. The second approach is the activity-on-node (AON) network, in which nodes represent activities and arcs the precedence relationships between them. This approach is activity oriented. Here, precedence relationships require that an activity not begin until all preceding activities have been completed. In AON networks, when there are multiple activities with no predecessors, it is usual to show them emanating from a common node called Start. When there are multiple activities with no successors, it is usual to show them connected to a node called Finish.

Time for an example, friends. Example – Network diagramming a Hospital Project In the interest of better serving the public, Metro Apollo Hospital has decided to relocate from Saritabihar to Badarpur, a large suburb that has no primary medical facility. The move to Badarpur will involve constructing a new hospital and making it operational. The work break down structure of it consists of 11 major project activities. The immediate predecessors for each activity are identified and shown in the following table. Activity A B C D E F G H I J K

Description Select administrative and medical staff Select site and do site survey Select equipment Prepare final construction plans and layout Bring utilities to the site Interview applicants and fill positions in nursing, support staff, maintenance, and security Purchase an take delivery of equipment Construct the hospital Develop an information system Install the equipment Train nurses and support staff

Immediate Predecessors A B B A C D A E, G, H F, I, J

The AON and AOA diagrams are shown below

I

A

K

F

Finish Start

B

C

G

D

H

E

Figure 26.2 AON Network for the Metro Hospital Project

J

F 2

8

I Dummy

K

C A

3

7 G

J Finish 9

Start 1

H

5

6

B D

E

4

Figure 26.3 AOA Network for the Metro Apollo Hospital project Both the AON and the AOA methods can accurately represent all the activities and precedence relationship in a project. Regardless of the method used, modeling a large project as a network forces the project team to identify the necessary activities and recognize the precedence relationship. If this preplanning is skipped, unexpected delays often occur. Activity 1 Irfan Bearings (P) Ltd is considering the replacement of the old machines in their factory by new advanced machines. The production manager has identified the activities given in the following table for this project. Draw the network diagram of the project and find the critical path with its duration. Activity A

Description Predecessors Analysis of costing with respect to purchase of new machines and sale of old machines as scrap

B

Approval of budget for purchase of new machines

C

Invite quotation of prices for new machines and choose B the supplier with best prices

D E

Invite tenders for sale of old machines B Advertise for additional new workers required for B operating the new machines Place the order for new machines C Select and train the new workers hired E Sell old machines to the selected buyer D Install the new machines H, F Start production G, I

F G H I J

A

Activity 2 Systems Software (P) Ltd is planning to develop a new software. It has identified the activities for the project as listed in the following table. The three estimates for all activities are also estimated and listed in the table. Find the expected time required for all the activities Activity Description A Plan the objectives of the project B Choose the appropriate operating system C Generate algorithm D Choose a suitable programming language E Write the program F Test the software G Get the approval for commercialization

Points to Ponder

Predecessors -

1

a

A

3

5

7

A A

6 4

10 6

14 8

B, C, D E F

8 2 1

9 4 3

10 6 5

2

m

3

b