By Paul Levin, PSP
The Mechanical Contractors Association of America (MCAA) has published over the years a series of factors that affect labor productivity resulting from various situational job conditions, such as stacking of trades, weather, overtime and learning curve. The factors have frequently been used by contractors to support loss of productivity (LOP) claims on projects resulting from delays, impacts and acceleration. In response to recent court rejections of use of the MCAA factors to calculate LOP damages, Prof. William Ibbs and Dr. Xiaodan Sun conducted a study to learn why and make suggestions for improvement.
This is an excellent paper and is very informative. Proposed Improvements to the MCAA Method for Quantifying Construction Loss of Productivity documents the history of the MCAA model, it identifies mistakes in its application, and it compares the MCAA model with other LOP studies and previous case decisions. The study found that since 2001, only two of nine cases where MCAA factors were used were successful, reversing a trend of five out of five prior to 2000. Read more.
This week's blog highlights from across the industry look at:
Benefits of Rooftop and Wall Vegetation Have Been Underestimated
San Francisco First in the Country to Require Rooftop Solar Panels; May Add Green Roofs
Interested in Green Roofs and Walls? Visit the Sky Gardens Blog
Here's a 4D building information model (BIM) of the planned new stadium for the LA Rams football team. A 4D model is one that ties objects in a 3D BIM model to activities in a CPM schedule (the 4th "D"). As the schedule is "played" on a computer display, each object in the model appears when it is encountered in the schedule like a time-lapse video. This 4D model, produced by the Conco Companies, a concrete design, construction and formwork supplier, is a good example how 4D works. Read more.