basics of project scheduling.pdf
DESCRIPTION
Project Planning Scheduling MonitoringTRANSCRIPT
IndexSl. no. Description Slide No.
THE BASICS
1 Definitions 3
2 Planning Process 4
3 Project Scheduling 5
4 Tools and Techniques used 6
5 Terminology used 7
6 Network Diagrams 8
7 PERT Networks 14
THE PRACTICAL ASPECT OF SCHEDULING
8 How do we start development of a schedule 18
9 Baselines updation and Tracking 19
10 How to cope up with a delay 21
The DefinitionsThe Definitions
Project
It is a temporary endeavor undertaken to create a unique product or service.
Project Planning
It is a part of Project Management, which relates to the use of schedules(e.g. Gantt Charts) to plan , report progress and subsequently control theprojectproject.
2
The Planning ProcessThe Planning Process
Define Objectives, Project Scope and System Requirements
Define specific work activities
Creation of Project Organization
Preparation of Schedule
Preparation of Budget and Resource plan
Preparation of a plan to review and control work performance
3
Project SchedulingProject Scheduling
It is an integral part of Project Planning which is concerned with the techniquesthat can be employed to manage the activities that need to be undertakenduring the development of a project.during the development of a project.
Objectives:Completing the project as early as possible by determining the earliest startand finish of each acti itand finish of each activityCalculating the likelihood a project will be completed within a certain timeperiodFinding the minimum cost schedule needed to complete the project by ag p p j ycertain dateInvestigating the results of possible delays in activity’s completion timeProgress controlSmoothing out resource allocation over the duration of the projectSmoothing out resource allocation over the duration of the project
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Tools and techniques used in schedulingTools and techniques used in scheduling
N kNetwork diagrams
PERTGantt Chart
PERT
CPMMilestone Chart
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Terminology usedTerminology used
Float/ SlackThe amount of time an activity can be delayed without delaying the project(t t l fl t) th l t t f ti it (f fl t)(total float) or the early start of any successor activity (free float)
MilestoneAn activity with zero duration which indicates the start or finish of a major taskac y e o du a o c d ca es e s a o s o a ajo as
Work Breakdown Structure (WBS)The overall project is subdivided into smaller elements called WorkBreakdown Structure (WBS) Its purpose is to divide the total project intoBreakdown Structure (WBS). Its purpose is to divide the total project intopieces of work called work packages which makes it easier to prepare projectschedules, cost estimates and to assign management and taskresponsibilitiesp
Critical PathIt is a sequence of project network activities having zero float. It determinesthe shortest time possible to complete the project
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the shortest time possible to complete the project
Network DiagramNetwork Diagram
It is a graphical representation of the project and it consists of a series ofactivities arranged in a logical sequence and show the interrelationshipbetween the activities.between the activities.Types:
AON(Activity on node) or PDM(Precedence Diagramming method)
A
C
D F
START FINISH
AOA(Activity on Arrow) or ADM(Arrow Diagramming Method)B E G
2 5A
DE H
1 3 6 8A
B
C
EF
G
H
I
J
7
4 7C G
Activity RelationshipsActivity Relationships
Finish to Finish (FF) Finish to Start (FS)
Activity A
Acti it B
Activity A
Activity B
Start to Finish (SF) Start to Start (SS)
Activity By
Start to Finish (SF) Start to Start (SS)
Activity A Activity A
Activity B Activity B
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Network AnalysisNetwork Analysis
Forward Pass: It gives the earliest expected event times i.e. Early Start (ES) and Early Finish (EF) for each activity.
Backward Pass: It gives the latest allowable event times i.e. Latest Start (LS) and Latest Finish (LF) for each activity.a d a es s ( ) o eac ac y
T t l Fl t LS ES LF EFTotal Float = LS- ES =LF- EF
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Critical Path Method (CPM)Critical Path Method (CPM)
Forward pass through the network and evaluation of ES & EF
Backward pass through the network and evaluation LS & LFLS & LF
Float = LS-ES= LF-EF
Identifying Critical Activities and Critical path
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90,10595,110
105,110110,115
149,170173,194
B15
C5
H21
0,900 90
90,11590 115
115,129115 129
129,149129 149
149,177166 194
194,204194 204
A90
D25
F14
G20
I28
K10
0,90 90,115
90 120
115,129 129,149
149 194
166,194 194,204
E30
J45
90,120119,149
149,194149,194
ES,EFLS,LF
30 45
Activity nameDuration
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Interpreting a schedule
The following parameters are essential to interpret a schedule
1. BL1 Early Start or Early Finish – Indicates when the activity should have started or finished
2. BL1 Late Start or Late Finish – Indicates maximum extent an activity can be delayed as per original plan
3. Total Float – Indicates how much float is available at a particular point in the schedule
4. Free Float – Indicates how much float can be actually used
5. Schedule Percentage Complete – How much should have been complete
6. Actual Percentage Complete – How much is actually complete
What does the Critical Path mean practically ?What does the Critical Path mean practically ?
• A set of activities that have no float connecting the START node with the FINISH node
• Longest path of the network
• The sum of the completion times for the activities on the critical path is the minimal completion time of theproject
• Delay of an activity on the critical path directly impacts the planned project completion dateDelay of an activity on the critical path directly impacts the planned project completion date
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The Baseline
Updated Schedule
Updated Schedule
ProgrammeProgramme Evaluation and Review Technique (PERT)Evaluation and Review Technique (PERT)
Use of probabilistic time estimates
For non-repetitive jobs (research and development work), where the time and cost estimates tendto be quite uncertainto be quite uncertain
Use of 3 time estimates :
• Optimistic time (to) : shortest possible time• Most likely time (tm) : best estimate of activity timeMost likely time (tm) : best estimate of activity time• Pessimistic time (tp) : longest time considering all odds
Expected time (te) = (to + 4tm + tp)
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Variance = ((tp – to)/6) 2
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Gantt chartGantt chart
• The Bar or Gantt Chart is used as a visual aid for tracking the progress of project activities
• Appropriate percentage of a bar is shaded to document the completed work• Appropriate percentage of a bar is shaded to document the completed work• The manager can easily see if the project is progressing on schedule
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Milestone ChartMilestone Chart
• A Milestone chart is similar to a Gantt Chart with the emphasis placed on taskcompletion• Milestones allow project management to much more accurately determineMilestones allow project management to much more accurately determinewhether or not the project is on schedule
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PRACTICAL ASPECT OF SCHEDULE DEVELOPMENT
How do we start development of a ScheduleHow do we start development of a Schedule
Fixing the milestones• It is very important that the activities are maintained within the milestone dates• These may be based on expert advise , thumb rule or any previous project• If LOI has been issued or the contract has been signed already then these dates should be taken into consideration• If owner approved vendor schedules are available then dates prescribed herein may also be used
Package Philosophy of the project should be frozen• Details on various packages should be available at your disposal
Any interfaces within the packages should be noted down since these may be critical in package interfacing in the schedule• Any interfaces within the packages should be noted down , since these may be critical in package interfacing in the schedule
Scope and WBS• Develop the Work Break Down Structure as desired and well within in the scope that has been frozen• Scope of the project should be understood well before one starts schedulingp p j g• WBS should be further broken down into smaller activities with tentative durations• Activities should belong to 3 basic areas viz Engineering , Procurement and Construction• Load the resources required for each activity individually
R i i d C tRevisions and Comments• Schedule should be further refined based on comments from all the package owners• Comments should be sent to all the concerned personnel via an official mail• Received comments should be incorporated wherever applicable , else the reasons for not incorporating the comments
should be given in a comment sheet
Baseline , Baseline , UpdationUpdation and Trackingand Tracking
Baseline Development and Updation• Once the schedule is developed it should be frozen into a baseline• Based on the project progress the schedule should be updatedp j p g p• Updation should be done either weekly or monthly based on the requirement
Tracking the schedule • Check for the critical path• Note the activities wherein zero or negative floats exists• Check if the milestone dates or the project end dates have moved
Information source for Information source for updationupdation
Major Information sources• Approved vendor reports• Updated Approved schedules from the vendor• Updated Approved schedules from the vendor• Consultant reports on drawings and documents• Vendor manufacturing data • Package owner inputs • Inputs from project owner
Vendor Reports• Vendor reports are essential inputs for the updation process• Vendor reports are essential inputs for the updation process• Standard report formats should be prescribed in the contract document• Contact persons should be detailed out in the “Co-ordination Procedure”• Vendor reports should be commented upon receipt and clarifications sought • Vendor reports should at least contain the Engineering , Procurement and Construction data • Reports have to be submitted at least on monthly basis
How to cope up with a Delay ?How to cope up with a Delay ?
• An activity is said to be delayed when it consumes all float available to it• Activity with zero float is a critical activity
The Critical Activity
• Any delay here can affect the project schedule
Delay Analysis and SolutionL k f h l i i f h h d l d k h “D i ” f h i i• Look for the last activity of the schedule and track the “Driver” of the activity
• Check if the driver has adequate float to crash the duration• Try to reduce dependency of the particular activity by using a different sequence of
execution • Check if the resources can be increased to reduce the duration of an activity
Final thought on schedulingFinal thought on scheduling
Schedule predictions will be accurate only when all the personnel involved in the project contributeto development and updation process
Schedule development should be started at Level 1 (L1) and further drilled down to other detailedSchedule development should be started at Level 1 (L1) and further drilled down to other detailedlevels like L2 , L3 , L4 etc. this results in a more precise and accurate schedule development
L1 dates may not be very accurate but the milestones should lie within the limits defined by LOI’sor contracts available
Schedules submitted by the contractors in later stages may be within limits defined by the L1schedule
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