Lean strives to eliminate anything that does not add value. Anything that does not add value is considered waste. Waste can be defined in various ways. In the laboratory setting, waste is often associated with waste of consumables, reagents, blood products, and tech time. The table below identifies sources of laboratory waste.
| Source of Waste | Lean Definition | Example |
| Waiting | Idle time between processes | Accumulating racks of chemistry samples and then running them as a single batch run. |
| Excess motion | Any unnecessary movement. Not only is it a waste of tech time, but it can lead to ergonomic problems. | Storing all reagents and supplies in the storage room rather than having a small amount stored at the bench area for easy access. |
| Overproduction | Upstream processes outpacing downstream processes, which then leads to excess work in progress. | Specimens piling up in the processing area (upstream process) waiting to be processed and taken to the testing area (downstream process). |
| Defect correction | Additional time and resources that are required to correct a defect. | Issuing a corrected report after an erroneous result is released. The laboratory must notify the health care provider, correct the report in the laboratory information system, and file a risk management report explaining the reason for issuing the corrected report. |
| Excess processing | Unnecessary steps in a process that do not add value. | Making slides for all hematology specimens, regardless of whether manual slide review is required. |
| Excess movement of materials | Unnecessary movement of materials from one place to another | Temperature-critical materials that should be delivered to the laboratory are instead delivered initially to the loading dock. |
| Inventory | Over-ordering or keeping items on hand that will never be used. | Ordering excessive amounts of reagents that may expire before being used. |
Lean also considers lost creativity a type of waste. Lean thinking encourages ideas and involves front-line workers in making changes. By encouraging employee creativity, an organization will realize less turnover and increased productivity from its employees.
