Fundamentals of scheduling

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


ProjectA project is finite, it has a specific

beginning and endpointsA project contains resources, typically

time, money and peopleA project is measurable


Activity (Schedule or Task)The activity is the basic building block of

a scheduleAn activity defines a measurable quantity

of work


DurationMeasurable unit to perform an activityTypically, durations are in work hours

or work days

RelationshipThe interdependency of one activity to

another


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


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


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


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


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


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


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


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


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


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?


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


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

Technology

Fundamentals of scheduling