Every Project is Unique

What is the significance of this statement when discussing inefficiency and/or productivity loss? It is important because differing project factors can affect how we view and collect loss factors and use some methods and calculations. Especially when comparisons to other projects are used. Many of these factors can directly affect efficiencies.

Some, but not necessarily all factors that can make projects (even by the same contractor/owner) unique:

  Design or capacity
  Varying site conditions such as soil, drainage, etc.
  Weather conditions such as climate and temperature
  Season changes/Ambient conditions/Weather Trends
  Manpower and labor conditions, such as union versus open shop, and skilled versus unskilled labor
  Experience factors such as learning curve and legacy data from previous projects
  Intangible factors such as morale, fatigue, and attitude, which leads to absenteeism, turnover, and crew size inefficiency
  Skilled labor availability and skill level
  Site access, Delivery methods, Communication Quality/availability
  Unplanned errors and omissions, work stoppages, delays, etc.
  Source and location of power and utilities and possible drainage/soil problems
  Governmental or regulatory requirements, Native Indian Regulations
  Material source, supply, and codes
  Different project team and supervision

Many Recognized Inefficiency Factors
Have Been Used
Correctly & Incorrectly

  Overtime/Multiple Shifts
  Morale and Attitude
  Stacking of Trades
  Joint Occupancy
  Beneficial Occupancy
  Concurrent Operations
  Absenteeism and Turnover
  Errors and Omissions
  Reassignment of Manpower
  Late Crew Build-up
  Crew Size Inefficiency
  Site Access/Obstacles/Crane Problems
  Security Check/Single Entry
  Learning Curve
  Ripple Effect
  Confined Space
  Hazardous Work Area
  Dilution of Supervision
  Shorter Daylight Hours
  Weather and Season Changes
  Rain, Snow, Wind
  Shift Work
  Working in Operating Areas
  Tools and Equipment Shortage
  Area Practices
  Proximity of Work
  Alternating, Staggered, or Rotating Work Schedules

You can find definition of these factors in the following linked documents:





Methods of Measuring
Efficiency Loss & Lost Productivity

Today there are several methods used, some better and more acceptable than others.

  Measured Mile (Most accepted method)
  Comparison to other projects as similar as possible
  Comparison to contractor’s bid, estimate, or plan (must show that past estimates were close to actuals on same past projects)
  Use of expert testimony to establish inefficiency
  Published inefficiency factors or studies:
  Bureau of Labor Statistics
  Business roundtable
  National Electrical Contractors Association
  Mechanical Contractors Association of America
  The U.S. Army Corps of Engineers Modification Impact Guide
  Practical exercises and case studies, and internal company studies

Measured Mile

Measured Mile is the preferred method, as determined by courts and construction arbitrators, for measuring lost productivity or inefficiency. The measured mile method compares the achieved productivity of two or more periods of performance for the same operation (activity)on the same project. The two periods of performance are called the unimpacted (efficient) or Quiescent and impacted (inefficient) or disrupted periods.

The reason that this method is the preferred is because of its reliance on the actual or achieved productivity. Why is the “actual or achieved productivity” feature of a measured mile method so important? It’s because the contractor’s achieved productivity removes variables or problems in the source data that could affect the accuracy of the analysis.

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James G. Zack, Jr.
Executive Director
Navigant Construction Forum,
Navigant Consulting, Inc.


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Impact Documents

Field Work Stoppage

Activity/Task Work Stoppage


Speed Memos/E-mails

Delay Notification

Cost Impact Notification