Velocity Accelerators®: Critical Chain Project Management

One of the areas we single-out for deeper discussion in a Pipeline workshop™ – what we call Velocity Accelerators® – deals with the imperative of replacing the current method of scheduling houses under construction.  Not one house.  Not every house, independently.

No – this is about the method of scheduling the entire portfolio of houses a builder has under construction at any point in time.

That’s because the nature of the workflow in homebuilding production is project portfolio management, managing what can be large amounts of work-in-process, managing what can be a large number of construction jobs.  Yes, there is workflow performed in processes, but those processes are a different type of workflow, and they are generally embedded in, and enabling and supporting of, the larger, more primary scheme of managing a project portfolio.

The process of building a home – what we call Start-to-Completion – is actually the management of multiple projects that share resources.  It is the structuring and the management of a portfolio of job schedules, with inter-dependencies and interactions of tasks and resources.

At its core, homebuilding is multi-project management.

The current method of project scheduling is known as the Critical Path Method (CPM), which evolved from the Program Evaluation and Review Technique (PERT) in the 1950s;  it has been in existence for almost 70 years;  it is the method used in every homebuilding ERP.

PERT and CPM were designed for one-off programs with large, complex structures (Polaris weapons system, the Manhattan Project), but the Critical Path Method has become the de facto standard for scheduling all types of projects:  aerospace/defense, software development, product development, research, and – yes – construction.

The problem with CPM is that it was not designed for managing a portfolio of projects, and it was not designed to function in environments where velocity is important, where faster cycle time and higher inventory turns are critical drivers of business outcomes.

Where it must contend with variation and uncertainty, CPM offers only a buffer of additional time – individual task durations lengthened to protect the completion date of each task, but not necessarily insuring the completion date of the project.

And – what is the cost of that added safety?  What is the cost of specifying 95% probabilities of completion over mean (50%) probability?

Statistically, it lengthens the job schedule by a factor of 1.64.  Which is how 90 day job schedules become 150 day job schedules.  Built-in safety that three well-known, yet typically un-checked, types of human behavior then conspire to waste.

For the most part, builders are oblivious to the effects of variation on their production system.  Yet, the cost of that variation is apparent and simple to calculate;  it is the Gross Income lost from all of the closings that never occurred, from houses that were never built with the capacity that was available;  for a profitable builder, it is Gross Income that would have certainly become Net Income, and ultimately, Net Profit.

It’s a lot of money.

Moreover, CPM considers task dependency (the predecessor-successor relationships of tasks) in its work breakdown structure, but it does nothing to resolve resource contention;  it does not consider situations in which tasks of different projects/jobs depend on the availability of resources that do not have sufficient capacity to meet the demand being placed upon them.

These two factors – dealing with variation and resolving resource conflict – should be anathema to homebuilders.

CPM was never designed to contend with the production environment homebuilding presents.  It is not the problem (the problem is variation and resource conflict), but CPM is benign to the solution.  ProChain Solutions’ Rob Newbold (Project Management in the Fast Lane) told me that he would go further, saying:  “CPM supports values that perpetuate the problems of homebuilders.”

Which brings us to Critical Chain Project Management.

Developed in 1997, Critical Chain addresses both task dependency and resource contention, and it replaces the padded durations intended to protect the completion date of every task with a smaller project buffer that is fully-capable of protecting the completion date of the project/job;  in the process, CCPM becomes much more aware of system capacity and constraints.

Understand what this different, changed approach means:  it means that Critical Chain substantially reduces the duration of projects – the cycle time of houses under construction – without impacting the reliability of their completion dates.

Consider the explanation of an exercise excerpted from the RB Builders: Lessons from the Pipeline© business case study being used in the upcoming Pipeline Workshop™ No. 11:

“RB Builders’ newly-acquired division has a construction schedule of 120 calendar days, but its calculated cycle time is actually 180 calendar days.  It is widely agreed that the division should be able to build its homes in far-less than the 120 days called for by the schedule, because that duration reflects ‘highly certain’ task durations.

“Switching from CPM to CCPM would immediately reduce the schedule from 120 days to 97 days, cutting the schedule by almost 20% with no diminution of confidence;  it would reduce the actual 180 day cycle time by almost half (46%).”

Critical Chain Project Management does more than just reduce the length of construction schedules.  It also specifies a set of rules preventing behaviors that consume (and waste) the safety CPM builds into task durations.  It installs a release mechanism that “pulls” starts into the system and keeps work-in-process at the levels required to produce faster cycle times.

It implements simple, visual tools to manage production.

Builders can put a number of these practices into place without changing the scheduling algorithms from Critical Path to Critical Chain.  They can use add-on applications that convert existing scheduling applications from CPM to CCPM.  They can implement standalone CCPM software applications.  However – Critical Chain will not be a complete, integrated solution for the homebuilding industry until its management technology providers wake up and address it.

It all starts with obtaining the knowledge necessary to insist on that change.

Come.  Participate.  Learn.  Insist on change.

 

Critical Chain Project Management is one of three Velocity Accelerators® (along with Business Process Improvement and Epic Partnering™) that will be explored at the next Pipeline workshop™, March 20-21, 2019, at the Ponte Vedra Inn and Club, in Ponte Vedra Beach, Florida.

Delivered by SAI Consulting and Continuum Advisory Group.

Sponsored by MiTek Industries and Specitup.

Cost is $895.00 per person;  for team pricing, inquire here (flgroves@saiconsulting.com)

Details:  www.buildervelocity.com