Craft Productivity Improvement

RT-143 Topic Summary
RT 143


This research evaluates the effectiveness of strategies used to improve labor productivity on construction projects. Specifically, it investigates the impacts that early design, early material delivery, and extra construction equipment have on craft productivity. This is called the buffer strategy. This research seeks to determine whether and to what extent, relatively larger stockpiles (buffers) of these three essential resources leads to improved productivity. An alternate approach to supplying sufficient physical resources for construction tasks is to spend additional effort in logistics and planning activities to insure that appropriate resources are delivered to the workers. This strategy, called the production planning strategy, suggests that instead of large stockpiles of materials, one carefully plans and delivers only the correct resources. Conceptually, production planning offsets its higher planning and logistics costs by avoiding double handling, interest, and waste costs that are associated with providing large stockpiles. Therefore, this study also investigates the effect of changes in construction planning and operations support personnel on labor productivity. Finally, this study investigates whether it is more cost effective to provide workers with the resources they need for productive work by using the buffer strategy or by using the project planning strategy.

Most construction firms use both strategies on their jobsites. However, increased use of buffers (e.g., larger stockpiles of materials, design, and equipment) reduces the need to plan production in detail by introducing flexibility into the production system. Conversely, precise production planning reduces the need for large buffers by ensuring that the correct materials, designs, and equipment are available for craft workers.

This publication offers readers a chance to compare these two strategies for productivity improvement. Both techniques have advantages and disadvantages. The ultimate goal is to choose the strategy that improves craft productivity and leads to successful project planning, execution, and startup.

Key Findings and Implementation Tools

1 : Material Buffers (Stockpiling) and Productivity

Relatively larger stockpiles of design, piping materials, or construction equipment all resulted in higher crew productivity. However, the buffer strategy for electrical work did not appear to be effective. No definitive relationship was found between electrical crew productivity and availability of design, material, or construction equipment. (RS143-1, p. 13)
Reference: (RS143-1)

2 : Material Buffers (Stockpiling) and Cost Effectiveness

Although the conventional approach of providing large piping buffers did improve productivity, it is not certain that the strategy is cost effective. The buffer strategy resulted in a relatively small labor savings stemming from productivity improvements against relatively high costs for providing the material buffers. The combination of stability to the production process and a small crew productivity improvement is sufficient to justify the added costs of providing large buffers. (RS143-1, p. 16)
Reference: (RS143-1)

3 : Production Management Strategy

The production management strategy proved more effective at improving crew productivity and is effective for both piping and electrical trades. The order of magnitude estimates indicate that the production management strategy is twice as cost effective as the buffer strategy. However, the pronounced improvement in the stability of crew performance was not observed with the production management strategy. (RS143-1 p. 10)
Reference: (RS143-1)

4 : Productivity Sensitivities

Both electrical and piping work productivity were extremely sensitive to changes in the degree of planning and production support available for the work crews. The implication is that shielding production through planning efforts improved the flow of work be either avoiding late or missing resources or providing increased expediting and logistic support to overcome late or missing resources. (RS143-1, p. 21)
Reference: (RS143-1)

Key Performance Indicators

Improved cost, Improved schedule, Improved craft productivity

Research Publications

Craft Labor Productivity - RS143-1

Publication Date: 03/2001 Type: Research Summary Pages: 26 Status: Supporting Product

Determinants of Jobsite Productivity - RR143-11

Publication Date: 01/2001 Type: Research Report Pages: 187 Status: Reference

Presentations from CII Events

Session - Craft Productivity Enhancements Update

Publication Date: Presenter: Number of Slides: 45 Event Code: PIW1008