In the Japanese analysis method called "Five Whys", the question, "Why?" is asked five times. When applying the Five Whys technique, the goal is to get to the problem's essence and then fix it. This approach utilizes the repetition of, "Why?"; after five times, the theory states that the nature of the problem as well as the solution becomes clear.9 Critical for the success of this technique is that decision-making be based on what is actually happening. That is why details in every step of the process must be identified.
An example of a workflow problem in the lab might be excessive repeats of chemistry tests.
The workflow planning team asked the Five Whys:
- Why are there so many test repeats? Reason: QC is frequently out of the control range.
- Why is QC out of control frequently? Reason: The control range is very narrow.
- Why is the control range very narrow? Reason: Control data submitted each month only includes data within 2 SD; this data along with previous data is used to create a new 2 SD range.
- Why is it that the only control data submitted falls within the 2 SD range? Reason: That is standard operating procedure.
- Why is that standard operating procedure? Reason: When the SOP was set up the control range was from the manufacturer's package insert in which they listed a wide 2 SD control range. Currently, the range is set by calculating the 2 SD range from the data submitted monthly for data analysis. Over time, the range can shrink.
Solution 1. Include data that falls outside the range but within 2.5 SD in calculating the control limits.
Solution 2. Adopt Westgard Rules that allow one control to be out of range if certain conditions (rules) prevail.10
