Fundamentals of Scheduling
Presented to the Cascadia Chapter,
SAVE International
January 12, 2011
by: John Langer AVS, Principal
John Langer Consultingwww.johnlangerconsulting.com
425-422-6986
© 2011 John Langer Consulting
Purpose of a Project The purpose of a project is to bring about change
Fundamentals
Scheduling Philosophy Scheduling Terms and Definitions Types of Schedules Relationships Resources
“When you don’t know where you are going, it is hard to tell when you get there”. Yogi Berra
Scheduling Philosophy
Why do you schedule? What do you schedule? When do you schedule?
Scheduling Philosophy (cont’d)
Why do you schedule? Better manage the project Control change Satisfy customer or contractual requirements Monitor and measure progress against goals
A schedule is a formalized method of managing time and resources
Scheduling Philosophy (cont’d)
What do you schedule? Milestones Activities required by contract or customer Activities critical to the performance of the project Changes to the original plan
A simple schedule that is used is far more valuable than the most detailed schedule created to satisfy a contractual requirement!
Scheduling Philosophy (cont’d) When do you schedule?
Prior to, or at the beginning of a project. This schedule is referred to as the “baseline”
At periodic intervals during the project. This is commonly referred to “updating”
If there are changes in the scope of the project If the project is substantially behind or ahead of
the baseline
“Even if you’re on the right track, you’ll get run over if you just sit there”. Will Rogers
Scheduling Terms and Definitions
Common scheduling terms and what they meanProjectActivity (Schedule or Task)DurationRelationshipBar Chart (Gantt)
Scheduling Terms and Definitions (cont’d)
LagCritical PathMilestoneFloatWork breakdown Structure (WBS)Resource
Scheduling Terms and Definitions (cont’d)
ProjectA project is finite, it has a specific
beginning and endpointsA project contains resources, typically
time, money and peopleA project is measurable
Scheduling Terms and Definitions (cont’d)
Activity (Schedule or Task)The activity is the basic building block of
a scheduleAn activity defines a measurable quantity
of work
Scheduling Terms and Definitions (cont’d)
DurationMeasurable unit to perform an activityTypically, durations are in work hours
or work days
RelationshipThe interdependency of one activity to
another
Scheduling Terms and Definitions (cont’d)
Bar Chart (Gantt) Graphical representation of a group of
activities making up a project, represented by bars along the horizontal time axis. Shows duration and planned sequence of activities
Lag The time associated in the relationship
between two activities. For example, stripping forms can not be completed until 10 days after concrete is placed. In this case, there is a 10 day lag between the activities
Scheduling Terms and Definitions (cont’d)
Critical Path The path or paths which are the series of
activities having zero float and must be completed on their scheduled dates or the project is in jeopardy
Milestone A point in time that signifies either the
beginning or the end of a series of related activities. A milestone has zero duration
Scheduling Terms and Definitions (cont’d)
Float A measure of leeway in activity performance.
Typical float types are “free float” and “total float”
Free float is the amount of time that an activity’s start can be delayed without affecting the early start of successor activities
Total float is the amount of time in starting or finishing an activity that will not affect the completion of the project
Scheduling Terms and Definitions (cont’d)
Work Breakdown Structure (WBS)Framework for organizing activities that
make up a project Resource
Anything needed to complete an activity: labor, materials, equipment, design, etc.
Types of Schedules
Milestone Time Scaled Logic Network Bar or Gantt Charts PERT
Types of Schedules
Milestone (Level 1)List of milestones and datesUsed to report at the summary level
Time Scaled Logic Network (Level 2)Graphical presentation of the scheduleLists activities and durationsShows logic ties and constraints
Milestone Chart
Design Kitchen
Designer Selected Plans Completed
Finalize Design
D1 D3 D5 D7 D9
Types of Schedules (cont’d)
Program Evaluation & Review Technique (PERT) Level 2
Graphic view that allows for easy evaluation of the flow of a project
Basic Logic Network
Task A
Task P
Task K
Task F
Task I
Task E
Task B
Task C
Task J
Task D
Task O
Task G
Task L
Task M
Task N
Task R
Task Q
Task H
Types of Schedules (cont’d)
Bar or Gantt Chart (Level 3)Graphical presentation of the scheduleLists activities and durationsMay show logicUsed for small projects
Design Kitchen
Select Designer Create Plans
Finalize Design
D1 D3 D5 D7 D9 D11
Bar (Gantt) Chart
Types of Schedules (cont’d)
Short duration schedulesDerived from the master scheduleTypically a bar chartUsed for near-term planningShows 2 weeks past, current week and 2
weeks forward
Relationships
Relationships are the interdependencies between one activity and another or group of activities
The four types of relationships are:Finish-to-StartStart-to-StartFinish-to-FinishStart-to-Finish
Relationships (cont’d)
Finish-to-StartThe most common type of scheduling
activity relationship. Simply stated, the start of the next activity is dependent upon the completion of the previous activity
For example, on a construction project you can’t pour the concrete until the reinforcing steel is in place
Relationships (cont’d)
Start-to-StartStart-to-Start relationship implies that an
activity can start once another specified activity has started
For example, the design phase can start as soon as the permitting process has started
Relationships (cont’d) Finish-to finish
Finish-to-Finish relationship implies that the completion of an activity is dependent upon the completion of another activity. This relation ship is commonly used with start-to-start relationships
For example, the software user’s manual can be started after the start of coding and testing but can’t be completed until coding and debugging is completed
Relationships (cont’d)
Start-to-FinishStart-to-Finish relationship implies that
an activity can’t be completed until the predecessor activity has started
This type of relationship is very rarely used
Resources
All projects consume resources! Resources are not just people:
resources can include money, material, equipment, and more.
How well these resources are allocated and monitored is a key measure of any project’s success or failure
Resources (Cont’d) Assigning resources to a project and
monitoring and reporting against the schedule provides the project manager with:Ability to estimate remaining workAbility to prepare accurate progress
paymentsAbility to provide historical dataAbility to address changes
Steps in Creating a Project Schedule
Activity Definition
Activity Sequencing
Estimating Activity Duration
Schedule
Development
Schedule Control
Developing a Project Schedule
Activity DefinitionAn activity must have a definable start
and endAn activity is used to develop a plan for
completing a project that sequences and schedules each activity
An activity is quantifiable and measurable
Developing a Project Schedule (Cont’d)
Activities shall relate to the WBS and allow for ease in quantifying and reporting
For example, in a construction schedule the activity might be F/R/P Slab-on-Grade, where F = form, R= place reinforcing, and P = place concrete. Breaking down the activity further would require additional resources to monitor for no additional return
Project2000
Design100
Procurement200
Construction300
Startup & Commissioning
400
Completion500
Sitework310
Warehouse320
Plant330
Office Complex340
Footings03301
Concrete Floor Slab
03005
Exterior Masonry Walls
04000
Steel Construction
05100
Roofing Systems07000
Interior Construction
09000
Mechanical15000
Electrical16000
Fine Grade02310
Edge From03105
Place Reinforcing03205
Embeds05510
Place Concrete -Pumped03305
Steel Trowel Finish03402
Cure and Protect03410
Labor
Consumables
Material
Equipment
Subcontract
Resources
Sample WBS for a Construction Project
Developing a Project Schedule (Cont’d)
Logic and relationshipsDevelop actual logic not placeholder
logicUse conventional Finish-to-Start logic to
develop relationships. This is the first pass at developing a schedule. As you refine the schedule you will incorporate Start-to-Start and Finish-to-Finish relationships
Developing a Project Schedule (Cont’d)
Calendars Is the project going to be scheduled in
hours or days?Will there be work activities that are
outside the normal work periods of the project?
Will the project include week-ends and holidays?
Developing a Project Schedule (Cont’d)
DurationsDoes the duration of each activity seem
practical and achievable?Nature of the task critical to the project
or fill-in work?Durations should be no less than 2-3 days
nor longer than 15 days
Developing a Project Schedule (Cont’d)
ResourcesWhat resources should be incorporated?Tie resources to the level of the activitiesA good place to begin assigning
resources is from the budget or cost estimate
Advanced Scheduling Topics
Resource Allocation Constraints Baselining the Plan Updating / Reporting Progress Controlling Change
Resource Allocation Team Building Matching Skills to Activities Estimating Hours Assigning to Activities Over allocated?
Resource Histogram
Shows the group and/or individual workload against available resources
Helps assess if the work can be done based on people involved
50%
100%
150%
200%
250%
300%
Graphics Support Overallocated: Allocated:
11/17 11/24 12/1 12/8 12/15 12/22 12/29 1/5 1/12 1/19 1/26 2/2 2/9 2/16 2/23 3/2 3/9 3/16 3/23ber December January February March
30 100 170 200 224.96 235 268.1 88.81 50 96.85 6.29
Constraints
Time
Dependencies
Assumptions
Physical
Time Constraints
No Constraint – Early Date
Start No Earlier Than
Finish No Later Than
As Late As Possible - JIT
Start No Later Than
Finish No Earlier Than
Dependency Constraints
Mandatory Dependencies Discretionary Dependencies External Dependencies
Baselining the Plan
Original Plan = Baseline Baseline vs. Current Schedule Changes to Baseline Performance Measurement Earned Value
Updating / Progressing
Percent CompleteTimeBudgetPhysical
Remaining Duration Remaining Work
Outputs From Progressing
“Schedule updates”
“Corrective action”
“Lessons learned”
Change Control Management
A famous general once said “To win the war, you must know the enemy.”
A famous project manager once said “We have met the enemy and the enemy is change.”
CHANGE
Manage change, or it will manage you!!!
Change Requests
A result of most ongoing projects Change in scope Change in schedule Change in cost (on cost type contracts)
Change is inevitable on ALL projects
Change Control Bottom Line
Proper Change ControlDropped Balls = Failed Project
THAT’S IT