Science Behind SchedulingWise Talk Thursdays

•Science Behind Scheduling

Topic

•One Hour

Planned Duration

•Open

Type of Interaction

•Management Sciences

Area of Knowledge

About the Presentation

Science Behind Scheduling

Definitio

n

•Brief History and Evaluation of Scheduling

•What is Scheduling

Explanation

•Definition of related terms

•The Process of Schedule Development

Exampl

e•Pra

ctical

Brief History of Scheduling

The concept of Scheduling is not new; Sun Tzu wrote about scheduling and strategy about 5000 years ago from a military prospective

Pyramids in Egypt (3000 years ago approx), Transcontinental railways (200 years) ago;

None of these could have been accomplished without some sort of scheduling i.e.,

understanding of activities and sequencing.

Evolution of Scheduling we know

Henry L Gantt An American engineer and social scientist invented a bar chart which we know as Gantt Chart -

1917

Kelley and Walker invented CPM -1956-57

The Pert Project invented the name “Critical Path” and everyone else borrowed it -1957

In 1968 PERT and CPM emerged as a standard nomenclatures

Dr. Fondhal invented a non- computerized methodology for scheduling which is being used by every scheduling

computer package today (Precedence Diagramming Method -1977 )

The Science of Scheduling as defined by Critical Path Analysis “CPA” celebrated its 50th Anniversary in 2007.

The term Schedule means Arrange or plan (an event) to take place at

a particular time.

Make arrangements for (someone or something) to do something.

What is Scheduling

Work Breakdown Structure

Work Package

Decomposition

Rolling Wave Planning

Schedule Compression

◦ Crashing

◦ Fast Tracking

Related Terms

Resource Leveling

Bottom-up Estimating

Project Network Diagram

PERT (Program Evaluation and Review Technique)

Related Terms

According to Project Management Institute, The Following is the process from Start to End in order to create a Project Schedule

Activity Definition

Activity Sequencing

Activity Resource Estimating

Activity Duration Estimating

Schedule Development

Schedule Control

Process of Schedule Development

Activity Definition is a process of defining the Activities which are part of scope of work in order to complete the Project

We drive the following things after Activity Definition process

◦Activity List◦Activity Attributes◦Milestone List

Process of Schedule Development

For Activity Sequencing , different Techniques can be used which are◦Precedence Diagramming Method (AON)◦Activities can have four types of

dependencies under this method which are Finish to Start Start to Start Start to Finish Finish to Finish

Process of Schedule Development

◦Arrow Diagramming Method◦Activities can have one type of dependency under this method which is Finish to Start

Process of Schedule Development

Durations in Project Network Diagram are calculated by using the following

Early Start Early Finish Late Start Late Finish Forward Pass Calculation Backward Pass Calculation

Process of Schedule Development

Activity Resource Estimation is a process where the resources (physical, human, infrastructure) are determined

Top down or Bottom up Estimation

Process of Schedule Development

Activity Duration Estimation is a process where the duration against each Activity is calculated.

Following Techniques can be used to calculated Duration for activity

◦ Analogous Estimating◦ Parametric Estimating◦ Three Point Estimate or PERT Estimate

Reserve Analysis

Process of Schedule Development

PERT Estimation uses the following concept

Process of Schedule Development

Process of Schedule Development

◦Following are some methods to develop the Project Schedule

◦Project Network Diagram Method

◦Critical Path Method, longest path in project network diagram

◦Critical Chain Method , adjusted schedule after incorporating dead lines and resources constraints in critical path method

Schedule Developement

Process of Schedule Development

Practical Example

Suppose we have a project with Following Activities

Start Requirement Analysis -TASK 1 – 3 Days Development - TASK 2 – 10 Days Installation - TASK 3 - 6 Days Deployment - TASK 4 - 8 Days UAT - TASK 5 - 4 Days Close

Practical Example

Second Step would be to find the dependencies among activities and draw a network diagram

Lets say we have only Finish to Start Relationship between activities as under

Start-TASK 1-TASK 2- TASK 5-End

Start –TASK 1-TASK3-TASK4-TASK5-End

Practical Example Let us Calculate Early Start and Early Finish

of Theses Tasks by Forward Pass.

Practical Example

Practical Example

Practical Example

Thank You