The Eight Wastes: The Enemy Against Lean

By: Lucía Armenta

As builders, we must recognize that waste is a major obstacle on the job site. We need to take steps to avoid, decrease, and ultimately eliminate waste wherever possible.

In the world of Lean, waste is defined as anything that doesn’t directly create value. Therefore, we must prioritize the waste reduction from the design phase to the construction phase. By doing so, we can increase efficiency, minimize costs, and ultimately provide greater value to our clients.

We can remember easily the eight wastes of lean thinking about the acronym D.O.W.N T.I.M.E. which stands for:

· Defects

· Overproduction

· Waiting

· Not-Utilizing Talent

· Transportation

· Inventory

· Motion

· Excess

1. Defects: These are errors, mistakes, or deficiencies that occur during the construction process. Examples include poor workmanship, incorrect installation, incorrect measurements, or insufficient quality control. Defects can also result from mistakes or omissions in the design or planning stages, such as incorrect specifications, incorrect drawings, or incorrect material selection. To minimize defects, lean construction focuses on improving the overall quality of workmanship and ensuring that all team members are trained to identify and address potential issues in the construction process.

2. Overproduction: This waste refers to producing more than what is required or producing it too early in the process, which can result in excess inventory, waste of resources, and decreased efficiency. It can occur when there is a lack of coordination between teams, inadequate planning, or unclear specifications. In the construction process, producing too many units of a certain material before it is needed can result in excess inventory. To avoid overproduction, lean construction emphasizes the importance of just-in-time production, where materials and products are produced only when needed in the construction process.

3. Waiting: Waiting wastes occur when workers or resources are idle or waiting for materials, information, or equipment to arrive, which results in delays and decreased efficiency. They can occur at any stage of the construction process, from design to project completion. Examples of waiting wastes include waiting for materials to arrive on the job site, waiting for instructions or approvals, waiting for equipment to become available, and others. To minimize waiting wastes, lean construction emphasizes the importance of efficient project planning, scheduling, and communication.

4. Non-utilized talent: This waste refers to the underutilization or untapped potential of workers and teams, which results in a loss of value and decreased efficiency. It can occur when workers are not given the opportunity to fully utilize their skills, knowledge, and experience or when workers are not empowered to make decisions or participate in the improvement process. To minimize non-utilized talent, lean construction emphasizes the importance of empowering workers, providing adequate training and resources, and promoting collaboration and communication.

5. Transportation: This waste refers to the movement of people, equipment, or materials that do not add value to the construction process and can lead to waste and inefficiency. It can occur when materials or equipment are transported unnecessarily or over long distances, resulting in increased costs, delays, and potential damage or loss. To minimize transportation waste, lean construction emphasizes the importance of proper coordination and planning of the construction process. This includes identifying potential transportation bottlenecks and inefficiencies, consolidating transportation activities where possible, and using just-in-time delivery of materials and equipment.

6. Inventory: This waste refers to materials, equipment, or other resources that are not immediately needed for the construction process and are stored or held more than what is necessary to meet customer demand. It can occur when excess materials or equipment are purchased or produced in anticipation of future needs, resulting in unnecessary costs, storage space, and potential waste or damage. To minimize inventory waste, lean construction emphasizes the importance of just-in-time delivery of materials and equipment, where the resources are delivered only when needed for the construction process.

7. Motion: This refers to any unnecessary or inefficient movement of people, equipment, or materials that does not add value to the construction process. It can occur when workers must repeatedly move between different work areas or when tools and equipment are not located in a convenient or easily accessible location, or when workers are not properly trained or have insufficient tools or equipment, resulting in excessive or inefficient movement. To minimize motion waste, Lean Construction emphasizes the importance of proper planning and organization of the construction process.

8. Excess: This refers to any unnecessary or surplus resources, including materials, equipment, and labour, that does not add value to the construction process. It can occur when more resources are used than needed to complete a task or meet customer demand, resulting in increased costs and potential waste or damage. Lean Construction emphasizes the importance of proper planning and resource allocation to minimize excess waste.

Finally, all the wastes of Lean construction are interrelated and can lead to inefficiencies and increased costs. Defects, overproduction, waiting, non-utilized talent, transportation, inventory, motion, and excess can occur at any stage of the construction process, from design to project completion. 

Each waste can contribute to the occurrence of other wastes and can create a cycle of waste that reduces efficiency and customer value. The goal of Lean construction is to minimize all types of waste through proper planning, coordination, and continuous improvement to optimize the flow of materials and information, reduce costs, and increase customer value.