Defects are errors in work or information that require rework, correction, or clarification. This leads to rework, one of the biggest causes of waste and a practice that commonly leads to projects being delivered late and over-budget.

If a designer receives new information that requires them to start their design over from scratch, that’s a defect. If a worker on the construction site puts up drywall incorrectly and needs to redo the entire section, that’s a defect. Miscommunication can also lead to defects if a team realizes they didn’t properly convey the strategy to those who were tasked with executing the job. In the AEC industry, many defects start as information issues before they show up in the field.

Over/Under Production is doing work before it’s needed, after it’s needed, or in the wrong amount for downstream teams. In other words: not producing the right work at the right time in the right amount as needed by the downstream work.

Perhaps you received more materials than you asked for, received them before or after you requested them, or both. This would go against the Lean virtues of just-in-time delivery (obtaining materials only as you need them and only taking as much as you need for production).

This leads to waiting & inventory waste because you are either not receiving materials you need and are then forced to wait (in the case of underproduction) or you receive too many materials that you now have no use for and need to store (overproduction). These can both lead to expanded costs during your project and wasted time.

For more on Over/Under Production Waste in the field, explore the Field Crew Huddle Youtube Channel.

Waiting waste occurs when people, information, or work incur unplanned delays between steps. Waiting is an extremely common type of waste that can occur in many different ways across design and construction projects.

If there’s an issue in the project that is preventing you from progressing but you’ve decided to wait until the weekly team meeting the next day to address it, that’s a type of waiting waste. If a worker is waiting to use a piece of equipment that they cannot complete their task without, that’s a type of waste.

More efficient processes can eliminate waiting waste. It’s important to practice identifying waste causes in the production process.

Not Utilizing Talent waste occurs when someone’s skills, ideas, and experience are not fully leveraged. This often shows up when the right people are not engaged in planning, problem-solving, or decision-making. If input isn’t respected through poorly utilized talent, creative solutions to complex problems are unable to present themselves.

Transportation waste is the unnecessary movement of materials or information between locations or systems. Unnecessary transportation occurs when planning is poor. This can also show up as moving information between systems, emails or formats.

Proper flow in a Lean design and construction process eliminates unnecessary transportation waste since materials, equipment, and the like are only moved as they are needed for the next stage of the process.

Inventory waste is excess materials, work, or information that is not needed at the moment. Excess inventory often hides problems and slows down flow. This is because most buffers are never used.

In both design and construction, excess inventory creates friction. Teams spend time moving materials or managing information that isn’t needed yet, and then waste additional effort sorting through drawings, data, or materials to find what is needed in the moment.

Motion waste is unnecessary movement or effort by people that does not add value. As mentioned above, unnecessary motion also occurs if workers are spending time searching for materials or information. This often shows up as searching for information or navigating multiple systems on a project or across an organization.

Unnecessary motion on job sites often occurs when workers must repeatedly shuttle across a room to retrieve materials stored away from their workstation or navigate around excess inventory that creates physical obstacles.

Extra Processing is doing more work, steps, or detail than is required to deliver value. This often shows up when processes include unnecessary approvals, excessive formatting, or levels of detail that don’t improve the outcome.

A common example of extra processing occurs in traditional Request for Information (RFI) workflows, where information is routed through multiple people before a decision is made, slowing the process without improving the quality of the answer.

Want to learn more about the 8 Wastes? Continue your learning journey with LCI eLearning! All eLearning courses, including Exploring the 8 Wastes, are free for LCI corporate members and are available to purchase in the LCI store for non-members.

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The Lean Construction Institute is committed to transforming the design and construction industry by providing Lean educational resources, conducting field research, and facilitating local and national Lean events. Explore supplementary resources below to further your understanding of the 8 wastes and how to mitigate them.