CPM Scheduling best practicies within the Construction Indistry

FUNDAMENTALS OF CPM SCHEDULING FOR
CONSTRUCTION PROJECT MANAGERS
Presented By: Michael A. Pink

www.construxsolutions.com 2
ABOUT THE PRESENTER: MICHAEL PINK
 Founder of Construx Solutions, LLC
 Inventor of the SmartPM Technology
 15 Years of Advisory Experience in Commercial Construction Industry
 Specialization in Project Controls, Risk Management, Dispute Avoidance
 Advisory Board Member for the School of Building Construction at GT
 Certified Planning and Scheduling Professional
 Certified Cost Engineer

COURSE OBJECTIVES
 Critical Path Method (CPM) Scheduling Explained
 Baseline CPM Schedules – Recommendations for Strong Schedules
 Schedule Updates – Best Practices for Generating “Usable” Updates
 Lean Construction Planning 101

THE BASICS – WHAT IS CPM?
 CPM Stands for “Critical Path Method”
 What is the “Critical Path”?
 Why are CPM Schedule’s Useful?
 Schedules in Excel and Visio are not CPM
Critical Path Method scheduling is a mathematically based technique (or algorithm)
that is used for scheduling an interdependent set’s of activities. The CPM method
first requires that all activities, durations, constraints and relationships are defined.
Once established, the algorithm generates a schedule based on the above
information. Within that schedule, there are 2 types of paths: “Critical” and “Non
Critical” Paths. The “Critical” path is the only path that extends from start to finish of
the project – with no room for delay. Every other path is considered “Non Critical”

THE BASICS – WHAT IS CPM?

THE BASICS – CPM SCHEDULING TERMINOLOGY
 Activity (or Task) – A discrete scheduled component of work to be performed during the
course of a project.
 Milestone – A significant event in the project schedule, such as an event restraining
future work (watertight milestone) or marking the completion of a major milestone
(substantial completion).
 Planned Duration – The total number of working days estimated to complete a
schedule activity.
 Resource Estimates – The estimated quantity (and types) of resources required to
perform each schedule activity.
 Logical Relationship – A dependency between two schedule activities, or between a
schedule activity and a schedule milestone.
 Predecessor – An activity required to be completed prior to the start of a
(successor) activity.
 Successor – An activity that follows the start/completion of a (predecessor) activity.
 Float – The number of days an activity can be delayed before impacting a successor (or
the end date of the project)

THE BASICS – BUILDING A CPM “BASELINE” SCHEDULE
Step 1: Choose a CPM Scheduling Technology (NOT Excel)
Step 2: List All Activities/Tasks Necessary to Build the Project
Step 3: Set Durations for Each Activity (Risk Adjusted if Possible)
Step 4: Apply Necessary Relationships amongst Activities
Step 5: Apply Necessary Constraints (Date, Crew, Calendars, etc.)
Additional Recommended Best Practices:
Step 6: Set Organizational Structure (Activity Codes or WBS)
Step 7: Resource/Cost Load Activities

THE BASICS – PREPARING THE ACTIVITY LIST
 Include all activities required to complete the work (this is a no brainer,
but still requires quite a bit of thought)
̶ This includes discussions with PM’s and Superintendents
̶ Subcontractor Schedule Submissions are useful prior to finalizing
 Activities should not be too broad and not to detailed
̶ 5 (min) – 20 (max) working days each (1 week to 1 month durations)
̶ A maximum of 100 activities per trade for the project
̶ Don’t exceed 2000 activities
 Crews and/or process/order are very important
̶ Early coordination discussions between CM’s and Subs is useful
̶ Must have achievable crew sizes
̶ Give some thought to the Activity Code / WBS Structure

THE BASICS – ESTIMATING ACTIVITY DURATIONS
 Consider Resources Required to estimate “Best Case” Durations:
̶ Visualize the Space and Estimate an Efficient Crew Size
̶ Use Estimate to Determined Planned Man-hours/days for the Activity at hand
̶ Divide Number of Estimated Man-days / Estimated Crew Size to get “Best
Case Scenario” Activity Duration.
̶ Enter into First Draft of CPM Schedule
 Review CPM Schedule and modify Durations to Account for Risk items:
̶ Need to Consider Crew Restraints
̶ Need to Consider Trade-Stacking
̶ Need to Consider Delay Issues that could arise
 Important: The more “Best Case” Durations that exist in the Schedule, the
higher the risk of budget overruns and delays.

THE BASICS – SETTING ACTIVITY RELATIONSHIPS
 “Logic” is the building blocks for a CPM schedule.
 Understanding of the Various Relationship Types:
̶ Finish to Start Relationship
̶ Start to Start Relationship
̶ Finish to Finish Relationship
̶ Start to Finish Relationship
 What is Lag?
 All activities should have a predecessor and successor
(except for the first and last activities/milestones)

EXAMPLES OF RELATIONSHIP TYPES – FINISH TO START
Predecessor
Successor
Finish-to-Start, Lag 0
Predecessor
Successor
Finish-to-Start, Lag 2
Predecessor
Successor
Finish-to-Start, Lag -2

EXAMPLES OF RELATIONSHIP TYPES – START TO START
Predecessor
Successor
Start-to-Start, Lag 0
Predecessor
Successor
Start-to-Start, Lag 2
Predecessor
Successor
Start-to-Start, Lag -2 Not Recommended

EXAMPLES OF RELATIONSHIP TYPES – FINISH TO FINISH
Predecessor
Successor
Finish-to-Finish, Lag 0
Predecessor
Successor
Finish-to-Finish, Lag 2
Predecessor
Successor
Finish-to-Finish, Lag -2
Not Recommended

THE BASICS – UNDERSTANDING CONSTRAINTS
 Start/Finish Constraints
̶ Availability Constraints
̶ Government Requirements
̶ Contractual
̶ No Real Predecessors/Successors
 Crew Management
̶ Crew Leveling
̶ Availability of Area
̶ Trade Stacking
 Calendar Constraints
̶ Union Requirements
̶ Acceleration Requirement
̶ Seasonal Constraints
̶ Preference
 Mandatory Start
 Mandatory Finish
 Start On or After
 Start On or Before
 Finish On or After
 Finish On or Before
 As Late as Possible
Constraint Types Examples

QUESTIONS?

SCHEDULE UPDATES – BASICS
 What is a Schedule Update?
 Why are Schedule Updates Useful?
 Recommended Scheduling Updating Process:
1. Activity Status Discussions between Schedulers and Project Management
2. Scheduler to upload activity status into the schedule and study results
3. Delays need to be discussed with Project Mgt., Supers and Subs
4. Conduct Planning/Mitigation Meetings with Site Team (PM’s, Supers, Subs)
5. Update go forward schedule based on discussions held (incl. mitigation Strategy)
 Schedulers who have limited knowledge on what’s going on in the field
should not modify logic or durations (ie. mitigate) “on the fly”

SCHEDULE UPDATING – DO’S AND DON’TS
DO DON’T
Status Schedules Updates in Real Time Issue Schedule Updates 1+ Months late
Update Schedules on a consistent basis (Week/Month) Update Schedules less than once per Month
Modify Plan based on Discussion’s Held in
Coordination/Strategy Meetings
Modify Plan without Field Input
Adjust Plan based on Historical Performance
Leave Incomplete Activity Durations pegged to the
Original Anticipated Durations
Incorporate Resource/Trade Constraints when Updating Crash the Schedule
Document (and substantiate) all modifications to
activity status, logic, durations, etc.
Update Activity Status and modify Logic, duration, etc.
w/o substantiating
Perform a Monthly Delay Analysis and Mitigation
Summary
Save Delay Analysis until the end of the Project
Produce and Utilize 3 Week Look-Ahead Schedules
Hope that everyone has a copy of the Latest CPM and
will figure it out themselves

SCHEDULE UPDATES – IMPORTANT RULES
 Use Historical Data/Info to Produce Realistic Future Projections
 Update Schedule with Data; Review; Modify
 Collaborate/Coordinate with Field Personnel to form Mitigation Strategies
 Use Feasible Logic Structures when Mitigating Delay
 Know the Resource Pool and Incorporate Crew Constraints
 Avoid Trade Stacking / Crew Spreading
 Have Discussions with other Stakeholders, Be Transparent.
 Fear the Crash – Crashing Schedules leads to claims
ALWAYS COMPARE CURRENT SCHEDULE TO THE APPROVED PLAN

CASE STUDY – UPDATING THE SCHEDULE AND
COMPARING TO THE ORIGINAL PLAN

UPDATE WEEK 1

UPDATE WEEK 2

UPDATE WEEK 3

QUESTIONS?

LEAN CONSTRUCTION 101
 Lean Construction results from the Toyota Lean Manufacturing System
 Lean Construction is belief that cost can be saved by minimizing waste
 Lean is a system of effectively organizing time and space in Commercial
Construction
 Focuses on Collaboration across all Phases of Construction with all
Stakeholders to minimize waste
 Performance Oversight Measures are Integral to Success
http://vimeo.com/63199577

FOCUS IS ON ELIMINATION OF WASTE
 Of the 3, Labor Costs are the largest “Risk” in the Construction Estimate.
 Labor Costs are the most highly correlated to cost fluctuations.
 Lean Construction is a system designed to minimize labor costs, by adding efficiencies.
 Managing Labor Cost Variances result in a Competitive Advantage in Construction

EXAMPLES OF WASTE
Transportation Material Handling Motion

LEAN PLANNING
 CPM scheduling is not enough, since CPM is Hypothetical;
 CPM schedules should be used as a basis for Lean Planning
 It is necessary to plan in real time to adjust and account for real world scenarios.
 Weekly Collaboration/Review Meetings are Required
̶ Beginning of the Week: 3-6 week look ahead / “Pull Planning” / Collaboration Sessions with
Field Team (PM’s, Supers, Foreman, Subs) to figure out near term schedules;
̶ Teams should discuss efficiencies, incorporate risk into activity durations, and determine
deliveries to prepare a “collaborated” 6 week plan (that all parties can agree to)
̶ Teams are left to Perform the next week in line with what was discussed;
̶ End of the week performance reviews should be held between Scheduler’s, PM’s and Field
members/Subs.
̶ Need to discuss impacts, correction measures and Rate Performance (info/data to be used for
following week’s meeting).
 Understanding Impacts is imperative to achieve for Lean Planning

LEAN SCHEDULING – ASSESSING BREAKDOWNS
Coordination

LEAN ASSEMBLY – SITE PLANNING

LEAN ASSEMBLY – DAILY HUDDLES

LEAN SUPPLY

PRESENTED BY: MICHAEL PINK
Contact Info:
C: 404 277 4387
O: 404 329 3000
mpink@construxsolutions.com
Feel free to contact me directly if
you have any additional questions
Sign up for our upcoming courses:
— Data Management and Performance Analysis
— Delay Analysis in Construction
— Construction Claims Review/Prep
Follow us on LinkedIn for more info.

CPM Scheduling best practicies within the Construction Indistry

Recommended

Recommended

More Related Content

What's hot

What's hot (19)

Viewers also liked

Viewers also liked (19)

Similar to CPM Scheduling best practicies within the Construction Indistry

Similar to CPM Scheduling best practicies within the Construction Indistry (20)

Recently uploaded

Recently uploaded (20)

CPM Scheduling best practicies within the Construction Indistry