The labor productivity of construction projects is low. This urges construction companies to increase their labor efficiency, particularly when demands grow and labor is scarce. This blog introduces an overview that helps practitioners identify causes of low productivity to find and eliminate the root causes.
Labor productivity is an essential indicator of labor efficiency within an industry, company, or project. As you might know, the productivity within the construction industry has been low over the last decades and still hasn’t achieved the gains of many other sectors . Companies might consider this a problem since labor costs comprise around half of the overall project costs. Therefore, low construction labor productivity (CLP) significantly affects project expenses and can influence the profitability of construction firms. Additionally, in some countries, the construction project backlog is rising, while the construction labor force is not big enough to get the job done. This urges construction companies to increase their labor productivity within their projects.
Graduating students and young practitioners are regularly asked to develop a CLP-improving plan. Total Quality Management has taught them that solving a problem starts by identifying the root causes, after which the company can design countermeasures. To find the root causes, the young investigator must understand the relations between the symptoms (low CLP in this case) and several levels of underlying causes. We can distinguish three levels of causes . First, causes that directly lead to a problem; are the most visible during an investigation. For instance, waiting time will decrease workers’ productivity. Second, causes that lead to the first-level causes. While they do not directly cause the problem, they form links in the chain of cause-and-effect relationships that ultimately create it. For example, the waiting time can be caused by a lack of materials. And finally, root causes will launch the entire cause and effect chain.
In the case of the example, a poor material order policy may be the reason. However, as a teacher and researcher, I have noticed that students and young practitioners often struggle to find the causes of low CLP. They tend to stick with a few possible causes hinted at by their colleagues and regularly don’t imagine non-obvious ones. But investigating those non-obvious causes often produces surprising and valuable results. Unfortunately, they are not accompanied by a sensei like Taiichi Ohno, who takes the young investigator to where the problem originates . Young practitioners lack experience in asking the right questions because they do not know what to ask. Becoming experienced takes years because every project has unique characteristics, and cause-effect relations will differ from project to project.
To help these young practitioners, and maybe the more experienced ones, I have created an overview of possible causes of low CLP (Figure 1). The summary finds its origin in a study comparing the impact of off-site and on-site construction on CLP for building projects . However, it will be generically applicable to every construction project.
Figure 1: Possible causes for low construction labor productivity
Figure 1 is based on 13 relevant studies that listed factors affecting CLP after surveying labor, technical staff members, (project) managers, consultants, contractors, developers, and clients. The context of the surveys differentiated in construction project type and country. Therefore, some causes are more likely to occur in specific projects than others. For instance, in some countries, the lack of literacy in labor is a significant issue. It will affect labor productivity if the workers cannot read the technical drawings and instructions.
The overview divides the causes into five groups. The first group consists of external factors, these are the factors that construction practitioners (almost) can’t change, for example, the weather. The second group contains management factors, such as the managers’ ability and health and safety management. The third includes labor-related factors such as motivation and absenteeism. The fourth group embodies factors concerning materials and equipment, such as their availability and quality. Finally, we distinguish several elements within the construction process. For instance, the quality of work, rework, and schedule pressure.
I believe overviews such as this can help identify the root causes of low CLP for any construction project. It encourages the practitioner to consider a minimum number of causes. The overview can also speed up the process because the practitioner doesn’t have to find the causes themselves. However, it can limit the practitioner’s commitment. For example, the practitioner may exclude his colleagues, assuming that the overview has all the answers. The outline is probably not comprehensive; investigators can find causes that are not on the list. Therefore, I advocate using this overview together with the standard root cause analysis techniques, not instead of them. And if you find a new cause of low labor productivity that is not on the list, let me know, and I will be happy to replenish it with new insights.