Once you have established Standard Work and your "Playbook", Standard Work is only effective if you "close the loop". In the graphic,
we describe the process of closing the loop. In this example, we show a typical "Day-by-the-hour" chart for a manufacturing process. Step 1 is to identify causes when they occur. The more frequently a team member can identify the cause of a Standard Work failure, the more accurate it will be. Therefore, it is important that this step be quick and easy to do. Step 2 is to quantify and prioritize the causes. Normally. a Pareto chart is best. At the appropriate frequency, the team, including support members, should meet and agree on the top one or two causes to be addressed. The third step is to identify the actions that will lead to sustainable process improvements in order to eliminate the cause. It is important at this step to ensure the true root cause has been identified. Using a 5 Whys process can be helpful here. We recommend that you have a structured, documented, repeatable process for identifying root causes. A common question when using a 5 Whys approach is, "How do you know when you have the root cause identified?". Typically you should stop asking why when:
1. You start to blame a person or their behavior. For example, "He forgot to do it it right", or "She needs re-training". These are not root causes.
2. It is something out of your control. For example, "It was hot outside" or "It's the economy".
or 3. You lose sight of the original context.
Step 4 is to understand the causality between action and result. It is good to make a plan and execute the plan efficiently. But, that's not the end. The end is when you have learned as a company whether or not your actions have had the desired effect. You will know this if the cause doesn't reoccur and your performance metric improves. Therefore, part of your review (gemba walk, asaichi meeting, daily standup, etc) has to involve learning. Ultimately, Standard Work hasn't been fully utilized until sustainable improvement is made and learning takes place.