CCPM

Critical
       Chain 
           Project  
                 Management

OUTLINE

  • Motivation & Overview
  • Steps in CCPM
  • An example

DEFINITION

Critical chain project management (CCPM) is a methodology for planning, executing and managing projects in single and multiproject environment.

HISTORY

MOTIVATION

Critical Chain Project Management was developed by Dr.Eli Goldratt and was first introduced to the market in his Theory of Constraints book "Critical Chain" in 1997

It was developed in response to many projects being dogged by poor performance manifested in:

  • Longer than expected durations
  • Frequently missed deadlines
  • Increased cost in excess of budget
  • Less deliverables than promised

PROBLEMS with Traditional Project Management

When planning for an upcoming project, estimates for task duration are required. In order for to be treated as realistic, much time is spent on ensuring that the estimates are accurate. Accurate estimates give us increased probability and high confidence on task completing on time.

  • Localized Risk Management
  • Student's Syndrome
  • Parkinson's Law
  • Multi-tasking

LOCALIZED RISK MANAGEMENT

"just in case!"

In order for the project to be completed on time, tasks need to be completed with certain degree of confidence...

This leads to resources giving a "safe" estimate rather than 50% confidence level.

STUDENT'S SYNDROME

People do not start to work full fledge until the deadline is near.

Happens to students.

PARKINSON'S LAW

Delay or "pacing" the completion of the task.

MULTI-TASKING

Management forces people to work on more than one task at a time

T1

T2

T3

T1

T1

T2

T2

T3

T3

Non Multi-tasking approach

Multi-tasking approach

  • Hidden Cost?
  • Inefficiency?

MULTI-TASKING ACTIVITY

OTHER PROBLEMS

Resources do not report tasks if they are finished early.

 

Delays are being passed on to the entire project, however, benefits are rarely passed.

 

Traditional techniques such as Critical Path Management do not address issue of embedded safety.

THE CRITICAL CHAIN

  • Longest chain of dependent tasks

Dependency refers to resources and resource contention across projects as well as dependencies of tasks themselves.

THE CRITICAL CHAIN

BENEFITS

To reduce the behaviors and time wasting associated with too much embedded safety.

 

CCPM recommends that task durations are cut half the length of a "normal" duration.

CCPM uses safety "buffers" to manage the impact of variation and uncertainty around the projects.

 

The safety at a task level is aggregated and moved to strategic points in the flow.

ESTIMATION

SAFETY

BUFFERS

PROJECT BUFFER

A project buffer is inserted at the end of the project network between the last task and completion date.

 

Any delays on the critical chain will consume the buffer.

BUFFERS

FEEDING BUFFER

Delays on paths of tasks feeding into longest path can impact the project by delaying a subsequent task on the critical chain.

 

To protect this, feeding buffers are inserted between the last task on a feeding chain and the critical chain.

BUFFERS

RESOURCE BUFFER

Resource buffers can be set to ensure that the appropriate people and skills are available to work on the critical chain tasks as soon as possible.

 

 

KEY CONCEPTS

  •  Priorities
  • Completion
  • Buffer management
  • Remaining duration

KEY CONCEPTS

  •  Priorities

All resources on a project are given clear and aligned priorities relating to the "health" of the Critical Chain relative to its associated buffer and hence the project as a whole.

 

A resource with more than one task open should normally be assigned to complete task that will jeopardize the Critical Chain.

KEY CONCEPTS

  •  Completion

When there is work available it should be progressed at the fastest possible speed.

 

Tasks are not left partially complete to remove the temptation to multi-task.

KEY CONCEPTS

  •  Buffer Management

The amount each buffer is consumed relative to the project progress tells us how badly the delays are effecting our committed delivery date.

 

If the variation throughout the project is uniform then the project should consume its project buffer at the rate tasks are completed.

KEY CONCEPTS

  • Remaining Duration

Tasks are monitored on their remaining duration, not their percentage complete.

 

Resources report upon tasks in progress based on the number of days they estimate until the task will be complete.

PATH     VS    CHAIN

CRITICAL PATH

CRITICAL CHAIN

  • Goes from start to end
  •  More subjective towards dates and milestones
  • Goes from start to project buffer
  • Takes resource contentions into account
  •  Problems: Student's Syndrome, Parkinson's Law etc..

Critical Chain Project Management Steps

5 hours

5 hours

5 hours

5 hours

5 hours

5 hours

Standard Conventional Project Schedule

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

Safety Buffers

Sequence Dependency

Resource Dependency

Safety Exclusion

5 hours

5 hours

5 hours

5 hours

5 hours

5 hours

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

5 hours

5 hours

5 hours

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

Safety Buffer Exclusion

5 hours

5 hours

5 hours

Resource Leveling

5 hours

5 hours

5 hours

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

5 hours

5 hours

5 hours

A7

A8

A9

A10

Critical chain is the sequence of dependent activities that determines the minimum time it will take a project to complete, taking into account both activity dependencies and resource constraints.

Critical Chain

Buffer Creation

5 hours

5 hours

5 hours

A1

A2

A3

A4

A5

A6

A9

A10

A11

5 hours

5 hours

5 hours

A7

A8

Critical Chain

FB

PB

FB

FB: Feeding Buffer

PB: Project Buffer

Feeding Chain

Project Buffer Incursion Chart

Advantages

Safety Buffer Exclusion

Resource Leveling

Buffer Creation

Overall benefits:

  • Cultivate team culture and motivate workforce
  • Low overall protection required
  • Higher coverage from exceptional scenarios on selective tasks
  • High success rate
  • Eliminates student's syndrome

 

  • Takes care of Parkinson's law
  • Avoids multi-tasking

 

  • Resolves resource and sequence dependencies
  • Feeder buffer protects critical chain

 

  • Project buffer protects whole project

The MMOR Barbecue Party

MMOR15

I'll ask Haider

& Tony for help!

Success...

Not a MESS!

...RBS?

...WBS?

TIMELINE?

Budget?

What kind of meat are we talking about?

Intense Project Scoping & Planning Meeting...

1. Send & Confirm Invitation

2. Buy Food & Drinks

3. Prepare Food

4. Mow Lawn

5. Take Tables Outside

6. Setup Tables

7. Heat Up Grill

Ravi

Haider

Tony

Tony

Haider

60Min

120Min

120Min

60Min

60Min

75Min

30Min

+15Min

+15Min

+15Min

+30Min

+30Min

Ravi

Haider

Tony

Ravi

+15Min

Haider

Ravi

Ravi

+30Min

#1

#2,5

-

-

#4

#3

#6

10AM

12PM

2PM

4PM

6PM

60+15Min

120+30Min

120+30Min

75+30Min

30+15

60+15Min

60+15Min

  • Start By 10AM
  • Guest Arrive By 6PM
  • Everything Ready By 6:45PM
  • "Safety time" - 150 Minutes

Execution

10:00AM

BBQ

PARTY!!!!

LOL

11:00AM

10:30AM

Execution

11:05AM

11:30AM

Oh boy..

Good thing

we planned ahead

Execution

Just need to

get it done

by 1PM..

11:30AM

Execution

11:50AM

Execution

12:10PM

Am I in heaven?

Execution

12:30PM

What am I

buying again?

Execution

1:05PM

1:15PM

Can't find the keys to garage...

1:30PM

Found it!

Execution

2:05PM

Where are the rest of the tables?

Execution

2:10PM

Execution

2:10PM

2:15PM

I can't work like this...

Execution

5:10PM

5:40PM

Execution

6:00PM

Execution

7:10PM

  • Process was messy
  • Barbeque delayed to 7:10PM (instead of 6:45PM)

What went Wrong?

10AM

12PM

2PM

4PM

6PM

60+15Min

120+30Min

120+30Min

75+30Min

30+15

60+15Min

60+15Min

As Plan

Supermarket busy, Distraction

Late start

Key search

Crowded Kitchen

Had to split up

Guest interference

What went Wrong?

MURPHY'S LAW

  • Bad Multitasking: Multitasking in supermarket
  • Student's Syndrome: Start task late thinking there is more then enough time

Safety buffers will be consumed no matter what. Only way to get around this is to make tasks important and urgent.

  • "Anything that can go wrong will go wrong."
  • Supermarket was crowded
  • Garage key was lost
  • Kitchen was too small
  • Guests arrived early

PARKINSON'S LAW

Only way to get around this is to add resources and buffers.

dilemma?

CCPM

  • Allocate minimum amount of time to a task so the task stays urgent
  • Keep a critical chain by making sure that resources will be available at the end of the previous task(s)
  • Use buffer to variances in task duration

CCPM

10AM

12PM

2PM

4PM

6PM

60Min

120Min

120Min

75Min

30Min

60Min

60Min

CCPM

10AM

12PM

2PM

4PM

6PM

60Min

120Min

120Min

75Min

30

60Min

60Min

FB:75Min

PB:105Min

  • Earliest due date: 5PM
  • Latest due date: 6:45PM
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