James McKay, PE AIA

1
MDCSystems
Providing Expert Solutions for Construction
Worldwide
Tricks, Traps and Ploys Used in Construction
Scheduling
presented by

• James McKay, PE AIA
• Vice President

• James Gorman
• Senior Consultant

2
Why Schedule ?

• Except in the middle of a battlefield, nowhere
  must men coordinate the movement of other men and
  all materials in the midst of such chaos and with
  such limited certainty of present facts and
  future occurrences as in a huge construction
  project.
• Blake Construction Co. vs. C.G. Cookby, Inc.

3
Why Schedule ?

• Formulate A Plan.
• Communicate The Plan.
• Set Goals.
• Measure Progress.
• Respond To Change.

4
Why Schedule ?

• Set Goals for the Project
• Progress
• Productivity
• Milestones

5
Why Schedule ?

• Progress Measurement
• Time
• Overall Completion
• Milestones
• Resource Consumption
• Money
• Manpower
• Equipment
• Material

6
Who Schedules ?

• Construction is the only industry where design
  and implementation are separated one from the
  other, and those engaged in design have
  significantly different interests and motivation
  than those responsible for the on-site
  construction.
• The Revay Report, v10, no.2

7
Who Schedules ?Schedule Considerations

• Owners
• Contractors
• Designers
• Suppliers

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Schedule Considerations

• Owner
• Funding Needs
• Permits
• Commissioning/Start-Up
• Occupancy Planning/Sales

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Schedule Considerations

• Owner
• Set overall project duration and completion dates
• Identify roles and interface requirements for
  major players
• Provide a baseline for progress and change impact
  measurement

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Schedule Considerations

• Owners Rep. Perspective
• Provide a Baseline for Measurement of Contractor
  Progress
• Provide a Basis for Progress Payment
• Deflect any risk exposure

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Schedule Considerations

• Contractor
• Prime Overall Execution of Work
• Sub More Detail on Fewer Activities

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Schedule Considerations

• Prime Contractor
• Fulfill Contract Requirement
• Provide Initial Plan for Work
• Provide Framework for Subs Work
• Updates Provide Basis for Progress Measurement
  and Payment
• Provides Basis for Claims arising from delays and
  scope changes

13
Schedule Considerations

• Designer
• Design Completion
• Permits/Applications
• Submission/Shop Drawing Review
• Progress Monitoring

14
Schedule Considerations

• Subcontractors Perspective
• Little Control or Input
• Provide Basis for work Plan
• GCs schedule may impose inefficiency
• Provide Basis for Progress Measurement and
  Payment.
• Provide Basis for Claims from Delay and Scope
  Changes

15
Schedule Considerations

• Supplier
• Submissions
• Shop drawings
• Fabrication
• Delivery/Lead Time

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Schedule Formats

• Bar Chart Schedules (Gantt Chart)
• PERT Chart Schedule
• Network Diagram Schedule
• Precedence Method Schedule
• Critical Path Method Schedule

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Bar Chart Schedule (Gantt Chart)
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Bar Chart Schedule (Gantt Chart)

• Strengths
• Most Common Schedule
• Common Sense Logic
• Quick Determination of Gross Progress
• Simplicity

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Bar Chart Schedule (Gantt Chart)

• Weaknesses
• Logic not Shown
• No Critical Path
• Difficult to Determine Overall Project Status
• Does not Help Establish Relative Sensitivity

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PERT Chart Schedule
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Computer Generated PERT Diagram
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PERT Chart Schedule

• Strengths
• Responds to Interrelationships Between Activities
• Produces Best Guess Completion Estimate
• Commonly used on Projects which have no
  Historical Information to Base Activity Duration
  Estimates

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PERT Chart Schedule

• Weaknesses
• Input can be Complex and Time Consuming
• Updating can be Onerous
• Does not Identify the Project Critical Path

24
Network Diagram Schedule
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Network Diagram Schedule

• Strengths
• Automatically accounts for Uneven Activity
  Durations
• Incorporates Resource Requirements such as
  Manpower, Material, Equipment, Money, etc.
• Identifies which Portions of a Project have
  Float Time and are not Driving the Overall Time
  to Complete the Project.

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Network Diagram Schedule

• Weaknesses
• Input can be Complex and Time Consuming
• Updating can be Onerous
• Results are Only as Good as the Input. Logic
  Flaws can be Hidden and Yield Faulty Projections.
• Pure Logic Diagrams can be Very Hard to Read and
  Understand.

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Precedence Method Schedule
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Precedence Method Schedule

• Strengths
• Does Show Inter-Activity Relationships and
  Constraints
• Forces Consideration of Preceding / Succeeding
  activities.

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Precedence Method Schedule

• Weaknesses
• Input can be Complex and Time Consuming
• Updating can be Onerous
• Results are Only as Good as the Input. Logic
  Flaws can be Hidden and Yield Faulty Projections.

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Critical Path Method Schedule(CPM)
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Critical Path Method Schedule (CPM)

• Strengths
• Time Scaled Logic Shown
• Logical Graphic Display
• Facilitates Alternative Planning
• Displays Critical Path
• Computer Generated Sorts of Key Data
• Quick Summary and Milestone Plots
• Relative Ease of Resource Loading

32
Critical Path Method Schedule (CPM)

• Weaknesses
• Computer Required
• Tedious Data Entry
• Complex Calculations of Time Requirements
• Logic Blocks to Quick Schedule Revisions
• Must be Maintained

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Schedule Specifications

• Assign responsibility for preparation.
• Define content.
• Designate software.
• Designate updating responsibility.
• Balance information needs with flexibility and
  complexity.

34
Schedule Specifications

• Contract Language
• Responsibility for Preparation
• Submission Dates
• Preliminary
• Final
• Approval by all parties
• Updates
• Frequency
• Content
• Tables/Graphics
• Changes since last Update
• Electronic Media

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Schedule Specifications

• Cost Load Schedule
• Advantages
• Simplifies billing
• Appears to tie progress to payment
• Disadvantages
• Complicates data input
• Payment needs often lead to manipulation

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Schedule Specifications

• Resource Loading
• Manpower (Trade)
• Cost
• Equipment
• Every additional resource adds to initial coding
  complexity and ongoing record keeping workload.

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Schedule Specifications

• Linking schedule to payment
• A good idea?

38
WHY USE A COMPUTER?

• Determine the Critical Path
• Identify driving activities
• Calculate Float
• Print out Reports (Lots of reports)
• By Early/Late Start/Finish
• By Float
• By Responsible Parties
• By Location

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WHY USE A COMPUTER?

• Do the Arithmetic
• Calculate Early Dates
• How soon can something start?
• Calculate Late dates
• How late can an activity start without delaying
  the project?

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TYPES OF DEPENDENCIES

• Finish to Start
• Start to Finish

• Start to Start
• Finish to Finish

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Basic Schedule Preparation Definitions

• Project Schedule
• An organized method of presenting in-formation on
  when activities need to be started, how long
  activities are planned to take, and when
  activities are planned to be completed.
• A schedule should also reflect the logical
  relationships between activities.

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Basic Schedule Preparation Definitions

• Critical Path
• The critical path is now identified as the path
  of activities, which contains the least amount of
  positive total float
• Float can be positive, negative or zero
• The critical path determines the length of the
  project
• Normally the longest chain or path of activities
  through the schedule

43
Basic Schedule Preparation Definitions

• As-Planned Schedule
• A schedule prepared by a contractor that depicts
  his planned approach to the execution of the work
  of his contract.

44
Basic Schedule Preparation Definitions

• Baseline Schedule
• An as-planned schedule which is refined and
  adjusted so that all parties agree that it may be
  utilized as the bench mark to measure actual
  progress during the project.
• The baseline schedule is the schedule against
  which progress and the impact of changes since
  the last schedule update are measured and
  analyzed.

45
Basic Schedule Preparation Definitions

• Schedule Update
• A version of the schedule that depicts the actual
  progress achieved and any changes made to the
  schedule during a specific time period usually
  one month.

46
Basic Schedule Preparation Definitions

• As-Built Schedule
• A time scaled graphic depiction of the historical
  record of events, activities, and progress on a
  given project.
• A historical record of a project in the form of a
  schedule showing actual activity start and finish
  dates.

47
Basic Schedule Preparation Definitions

• Activity
• Most detailed work unit that is tracked in a
  project schedule
• Contains all detailed information about the work
  to be performed
• Also known as a task or item

48
Basic Schedule Preparation Definitions

• Float
• The amount of time an activity can be delayed
  without delaying the overall completion date.
  Also defined as the time between when an activity
  can start and when it must start.
• Ownership
• Types
• Free
• Total

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Basic Schedule Preparation Definitions

• Contingency vs. Float
• Whats the Difference?
• Why is it Important?

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Basic Schedule Preparation Definitions

• Delay
• An event or condition that results in the project
  completion or an activity or group of activities
  starting or completing later than originally
  planned.
• Types
• Excusable Non-excusable
• Compensable Non-compensable
• Critical Concurrent

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Basic Schedule Preparation Definitions

• Acceleration
• The performance of construction work at a faster
  rate than anticipated in the original schedule.
  This is accomplished by increasing labor and
  other resources.
• Types
• Constructive
• Directed

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Basic Schedule Preparation Definitions

• Disruption
• Start/Stop Iteration
• Out of Sequence Work
• Delays to Approvals
• Trade Stacking
• Manpower
• Environment/Weather

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Basic Schedule Preparation Definitions

• Trade Stacking
• Having more prime or subcontractor work crews
  per-forming different types of construction work
  in the same area than is efficient for the flow
  of work being performed.

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Basic Schedule Preparation

• Elements included in all Schedules
• Milestones
• Notice to Proceed
• Phasing Requirements
• Testing/Acceptance
• Operational Date
• Beneficial Use
• Substantial Completion

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Determine Project Scope Define Calendar
• Define Activities Determine Relationships
• Assign Durations Assign Responsibility
• Assign Resources Process Schedule
• Monitor Schedule

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Review Contract Documents
• Construction Plans
• Contract Specifications
• Schedule Specifications
• Material Specifications

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Review Contract Documents
• Project Construction Plans
• Determine construction layout and phasing
  requirements
• Determine material requirements (Quantity,
  quality installation)
• Determine site constraints
• Identify coordination/problem areas

58
Basic Schedule Preparation

• Basic Schedule Development Steps
• Review Contract Specifications
• Notice to Proceed
• Required Milestones
• Phasing
• Substantial Completion
• Turnover (Prior to Completion)

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Review Schedule Specifications
• Required activity durations
• Schedule submittal requirements
• Update submittal requirements
• Designer submittal review time requirements
• Procedures for any change in scope

60
Basic Schedule Preparation

• Basic Schedule Development Steps
• Review Material Specifications
• Shop Drawing/Submittal Requirements
• Materials Supplied by Others
• Sole Source Suppliers/Materials
• Review time turnaround
• Delivery times

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Analyze the Project
• Create Activity IDs
• Determine Activity Duration
• Develop Logic Relationships

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Create Activities
• Task ? Design
• Independent ? Procurement
• Meeting ? Approval
• Start Milestone ? Test
• Finish Milestone ? Punchlist

63
Basic Schedule Preparation

• Basic Schedule Development Steps
• Activities from the WBS
• Drawings and Specifications
• Activity Duration from Experience/Calculation
• Logic from Experience/Planning
• Start/Stop dates from Requirements/Phasing
• Concurrent Activities from Experience/Interface
  Requirements

64
Basic Schedule Preparation

• Basic Schedule Development Steps
• Develop Coding Structure
• Responsibility
• Location
• Trade
• Phase
• Sequence

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Determine Activity Duration
• From experience/calculation
• Manpower Availability Productivity
• Procurement Consider time to prepare submittal,
  design review, fabrication and delivery time
• Specialty Long Lead Items

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Develop Logic Relationships
• From experience/planning
• All Activities should have predecessors and
  successors
• Ideally there should be only two Activities with
  open end (Notice to Proceed and Project
  Completion)
• Identify constraints
• From contract
• Physical limits
• Overlap with other activities

67
Basic Schedule Preparation

• Basic Schedule Development Steps
• Key Activities/Interfaces
• Work of Other Contractors
• Long Lead Time Materials/Equipment
• Owner Furnished Material/Equipment
• Phasing Requirements

68
Basic Schedule Preparation

• Basic Schedule Development Steps
• Incorporate Resource Considerations
• Contract Requirements
• Milestones
• Phasing
• Work Restrictions
• Resource Constraints
• Manpower
• Equipment
• Weather

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Basic Schedule Preparation

• Basic Schedule Development Steps
• Resource Considerations
• Availability of Management Team
• Manpower Availability Quality
• Equipment Subcontractors
• Specialty Subcontractors
• Materials Lead Time
• Site Access Limits

70
Basic Schedule Preparation

• Common Problems that Affect Schedule
• Differing Conditions - Active Interference
• Access to Site - Disruption
• Availability of Site - Work Sequence
• Technology Development - Weather
• Review and Approval process

71
Basic Schedule Preparation Common Problems that
Affect Schedule

• Interferences
• Changes
• Materials
• Technical Error
• Acceleration
• Directed
• Constructive

• Impossibility of Performance
• Superior Knowledge
• Defective Plans and/or Specifications

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Basic Schedule Preparation

• Schedule Check Points
• Does Schedule Conform to Contract Dates?
• Are Milestones Indicated?
• Is Phasing Currently Shown?
• Is There a Logical Sequence of Activities?
• Activity Durations are Reasonable
• Do Resource Allocations Seem Reasonable?
• Interface Work is Indicated
• Is Testing Indicated?
• Critical Path Indicated

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TYPICAL SCHEDULE
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COMMON SCHEDULE DEVELOPMENT ERRORS

• Missing Scope
• Unrealistic Original Durations
• Missing Restraints
• Over Restraints
• Reliance on Fixed Dates

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Basic Schedule Preparation

• Common Scheduling Software
• Primavera
• Microsoft Project
• SureTrak
• Timeline

76
Schedule Update Techniques

• Perform Schedule Update.
• Depict Actual Status.
• Make Projections Using Existing Schedule Logic
  and Durations.
• Determine the Predicted End Date.

77
Schedule Update Techniques

• Compare Schedule Data with As-built/Completed
  Project History.
• Use Independent Data Sources for Verification.
• Logs
• Pictures/Video
• Progress reports
• Compare Planned vs. Actual Durations.
• Similar Activities
• Work in Progress

78
Schedule Update Preparation

• Updates
• Establish data date.
• Enter all start dates of activities in progress.
• Enter completion dates of completed activities.
• Enter percent complete of activities that have
  started.
• SCHEDULE
• Analyze new logic of critical path and other
  activities.
• Develop strategy to recover time if required.
• Identify record all changes made since last
  update.

79
Basic Schedule Preparation

• Change Order Impact
• Fragnet or New Activities Required as Part of Any
  Change Request or Extension of Time Request.
• Contract-Required Prior Approval before Work can
  be Performed.
• Potential Impact on Unaffected Work

80
Basic Schedule Preparation

• Remember
• Schedule development and re-planning is an art as
  well as a science.
• If you feed a computer garbage data it will
  produce garbage schedules.
• Apply common sense/parametric thinking to analyze
  computer output.
• Good schedules and honest analysis ?good project
  management.

81
Problem / Response

• Recognize symptoms.
• Identify cause.
• Respond appropriately.
• Recover if possible.

82
Problem / Response Lack of Progress

• Start with critical path activities.
• Track progress by
• Location
• Date
• Subcontractor/Craft

• Identify constraints
• Manpower
• Equipment
• Access
• Preceding work
• Weather
• Identify appropriate response once true cause is
  known.

83
Problem / Response

• Only solve the problem you actually have
• Selective overtime v. job wide
• Selective additional manpower
• Notify owner and get direction

84
Scheduling Specifications

• Information Needs
• Content - Format
• Distribution/Updates
• Level of Detail
• Resources (In or Out?)
• Acceptance/Approval
• Owner - Subs

85
MDCSystems
Providing Expert Solutions for Construction
Worldwide
COMMON SCHEDULING PROBLEMS and TRICKS

• Tailored Output to Suit the Audience
• Key Concepts
• Just because a computer generated a report
  doesnt mean that it makes any sense.
• The difference between data and information

86
Signs or Symptoms That Trouble is Brewing
87
Signs or Symptoms That Trouble is Brewing
88
Scheduling Problems/Tricks

• Logic Manipulation
• Improper Use of Constraints
• Preconceived Critical Path
• Duration Manipulation
• Calendar Manipulation

• Lag Magic
• Hidden Float
• Calculation Manipulation
• Concurrency Arguments
• Activity Interruption Misrepresentation

89
Scheduling Problems/Tricks

• Logic Manipulation
• Common Sense
• Physical Reality
• Unconnected Activities
• No Predecessors/Successors
• Float Manipulation
• Adequate Detail

90
Scheduling Problems/Tricks

• Improper Constraints
• Artificially Fix Dates
• Early/Late Start/Finish
• Not Earlier/Later
• Must Start
• Behind the scenes
• Confuses Critical Path Calculations
• Resource Manipulation can distort Schedule

91
Scheduling Problems/Tricks

• Preconceived Critical Path
• Just Like another project
• Its always critical
• Insufficient Detail

92
Scheduling Problems/Tricks

• Duration Manipulation - I
• Float Control
• Critical Path Manipulation
• Real vs Earned Progress
• Revised Original Durations

93
Scheduling Problems/Tricks

• Duration Manipulation - II
• First and Last Day
• What about everything in between?
• Variable Calendars
• Retroactive Orig. Duration Changes
• Resource Impacts Limit Durations
• Alternate Shifting to Alter Future Durations

94
Scheduling Problems/Tricks

• Calendar Manipulation
• One Size doesnt fit all
• Behind the scenes
• Some things just cant be compressed
• Weather Impacts

95
VARYING CALENDARS ALTER FLOAT NUMBERS
96
Scheduling Problems/Tricks

• Improper Relationships Can Lead to Trouble
• Leads/Lags Hide Impacts
• Hard to Detect Sneaky
• Trade/Sub Flow Wrong

97
Scheduling Problems/Tricks

• Different Schedules for Different Audiences
• Contractor to Owner
• Contractor to Subs
• Project Manager to the Boss

98
Scheduling Problems/Tricks

• Scheduling Calculations Change
• Truly Sneaky and Behind the Scenes
• Retained Logic
• Progress Override
• Automatic Resource Leveling
• Criticality Indications
• Float Calculation Basis

99
Scheduling Problems/Tricks

• Concurrency Manipulation
• Difficult to prove exclusive Causation
• Usually Easy to get time but not from Owner
• Very Hard for Subs to recover
• GC usually controls their activities

100
Scheduling Problems/Tricks

• Solutions
• Each Project is Unique
• Match the Schedule to the Project
• Dont Overcomplicate Things
• Consider the Use the Schedule Will Provide
• Planning Management
• Payment Claims

101
Scheduling Problems/Tricks

• Solutions
• Qualified Personnel/Training
• Proper use of Software
• Informative Reports
• Training / Responsibility
• Adequate Funding (No Free Lunch)

102
Scheduling Specifications

• Information Needs
• Content - Format
• Distribution/Updates
• Level of Detail
• Resources (In or Out?)
• Acceptance/Approval
• Owner - Subs