In a webinar on lost productivity in construction conducted this week by Dr. William Ibbs, University of California professor and founder of the Ibbs Consulting Group, reference was made to a recent report on changes in construction and effect on productivity. The report, Change and the Loss of Productivity in Construction: A Field Guide, authored by Dr. Ibbs and Caroline Vaughn, is itself primarily based on a 2007 dissertation by Dr. Seulkee Lee. Dr. Lee's dissertation -- Understanding and Quantifying the Impact of Changes on Construction Lab Productivity: Integration of Productivity Factors and Quantification Methods -- took a detailed look at numerous methods for quantifying productivity losses.
The Ibbs and Vaughn field guide is intended to be an introduction to change, change management and field productivity on construction sites. This includes "...an overview of productivity factors, types of change, the importance of managements' actions and decisions, and how to quantify productivity losses." The 90-page report is divided into two sections. The first part is devoted to defining and recognizing change and productivity factors. The second part covers the quantification of change and loss of productivity.
What caught our attention was a list in chapter one of "Seven Categories of Productivity Factors." According to the authors, "...a productivity factor is a condition that influences productivity." The authors describe how these various categories either impact productivity directly or lead to more disruption. More than 40 unique factors are listed in the chapter; this in itself illustrates how complex the construction process is and the need for construction project staff to give full attention to managing productivity, particularly when encountering changes. The seven categories are:
- Project and Contract Factors
- Location and Environment Factors
- Project Team (Owner, Contractor and Architect) Factors
- Managerial Actions and Decisions During Project Execution
- Disruptive Events and Signs on Sites
- Human (Worker) Reactions
- External Factors
The Ibbs and Vaughn guide is well worth reading. While the principal target audience is the contractor's field and management staff, all parties to the construction contract should be aware of the impact of changes on productivity. This will provide a better understanding of why impact and delays occur, and may help owners and others avoid actions that could have a disruptive effect. The report is free and may be downloaded by clicking here.