July 4, 2022

Top 3 Schedule Problems

Top 3 Schedule Problems

I have yet to meet a person or team that acted to aid the late delivery of a construction project. In fact, professionals often expend heroic levels of effort and creativity towards improving their schedules. Best efforts using standard management responses to delays like adding more resources (people, extra work shifts, weekend work, and equipment) or invoking contract penalty clauses rarely improve the project's throughput or flow. Why? 

"CPM versus Flow" was going to be the topic of debate for an upcoming The EBFC Show live stream. As soon as the event announcement went public, it became clear that this topic was emotionally charged. A mixed bag of comments like these poured in:

"CPM kills people." 

"I've used CPM my whole career. People just don't know how to use it right." 

"Rigorous communication and CPM always result in on-time project delivery."

"Lean Construction methods helped me finish my project ahead of schedule and led to a promotion."

"Focus on flow. Methods like Takt, Scrum, and Last Planner enable it."

After much one-on-one dialogue, it became clearer that people believe you can achieve flow with good CPM or only achieve flow with alternative methods without CPM, and it turned out not to be an either-or option. The scheduling problem experiences of numerous professionals had multiple threads leading back to these top three: 

Problem #1: Variation

Problem #2: Prioritization

Problem #3: Suboptimal Flow


Today's worldwide project management standard for planning and scheduling uses software for Critical Path Method (CPM) schedules. CPM schedules are also known as Gantt Charts or waterfall schedules and date back to the early 1900s. Contracts often require these schedules, which include conditions for recovery schedules and liquidated damages for late project delivery. The Project Management Institute's Project Management Body of Knowledge (PMBOK) states that the critical path method is "the sequence of scheduled activities that determines the duration of the project." In other words, if the critical path tasks finish as planned, your project ends as forecasted. If those same tasks finish later, your project is predicted to finish equally later. Non-critical tasks have float, the number of days that the task can be delayed without impacting the project's planned completion. This standard requires replanning and recovery schedules when critical path tasks encounter variations that result in activity completion delays. Even simple projects will experience variation, and complicated to complex projects will experience exponentially more of it. 

Problem #1: Variation

The Statistical Quality Control Handbook says, "Everything varies." The same is valid for design and construction, and no two processes or things are precisely alike. "Groups of things from a constant system of causes tend to be predictable." A schedule forecasts outcomes, and with observations, we still can't predict the accuracy of any one task better than a coin toss. Research indicates that planned construction schedule activities only have a 48% - 54% completion accuracy. Predictions become possible for groups of work activities where patterns can be observed. We can observe patterns and manage towards desired outcomes using simple communication strategies like daily huddles or visual management in alternative scheduling frameworks. 

Problem #2: Prioritization

Schedules prioritize the sequence of work that must be done, and this prioritization determines what work project teams need to do now versus what needs to be done later. When logic-tied activities indicate a project schedule delay, people often modify logic and overlap later activities. Sometimes schedules are not adequately logic tied, and analysis reveals many later period overlapping work activities. Their intention is usually sound, thinking problems today may be better solved later due to other more urgent work in need of attention now. This is not a sustainable approach since it reduces prioritization. There is a subtle tipping point when the team's ability to handle numerous priorities passes. Alarms won't immediately sound, but you will notice clues when walking your project's critical path work activities. You will see work starting in the planned areas but not finishing. You will hear more calls for increasing crew sizes, adding more crews, or asking people to work longer.  

Problem #3: Suboptimal Flow

Perfect flow is delivering the project to the customer when they desire it. Because of variation, among other reasons, perfect flow is not yet possible, but optimized workflow is possible. Suboptimal flow occurs when project conditions or systems prohibit or cause friction in doing the amount of work to a level of completion that results in ideal handoffs to the following value creator. Contrary to standard practices, you have to limit work in progress to improve flow; this is where other methods make sense. 

CPM alternatives such as Last Planner System, Takt Scheduling, and Scrum date back to the 1990s, with older methods such as the Line of Balance Scheduling Technique and Critical Chain Project MGMT (CCPM) dating back even earlier. These alternative methods limit work in progress to enable higher flow or flow efficiency. Essentially, this is a ratio between active working time and total available time. Limiting work in progress addresses the top three schedule problems:

  1. Less work in progress equates to less variation to manage. Teams focus on making work ready to start at the right time.
  2. Less work in progress equates to fewer priorities. Teams are aligned on what is needed to do now versus later. 
  3. Less work in progress equates to more optimized flow. Teams work on the right activities at the right time and to the right level of completion. 

Are you ready to improve your project's throughput? Evaluate your project to see if you have any of the top three schedule problems. Take steps to plan differently, reduce the risk of schedule delays, and learn which alternative methods help solve your schedule delivery problems. Combat flow inefficiency, resource stacking, and complexity. What other types of schedule problems do you see most?


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