Subscriber only lesson.
Sign up to this course to view this lesson.
About this lesson
The As-is metrics are the measured current state of the process or problem. It is not the best-case, the worst-case, or the “as-designed” case; it is the current average performance of the process or problem.
The As-Is metrics are the measured current state of the process or problem. It is not the best-case, the worst-case, or the “as-designed” case; it is the current average performance of the process or problem.
When to use
By the end of the Measure phase of a Lean Six Sigma project the team should be able to calculate the As-Is metrics for the process or problem.
As-Is metrics are calculated based upon measurements at process steps. In some cases, these metrics are totalled for the entire process. The purpose of the As-Is metrics is to reflect the total process impact on the customer. These metrics should show what is really happening and what the customer experiences. Among the most common metrics are:
- Total Time (ToT) – This is the entire amount of elapsed time from the beginning to the end of each process step. It is often then totalled for the entire process. It includes nights, weekends, and holidays. It is usually calculated by measuring the time from the start of the first step until the start of the next step.
- Process Value-Added Time (VAT) – This is the sum of the value-added time for each step in the straight line flow of the value stream. It is often totalled for the entire process. For those steps with no value-added time, they contribute nothing to this number. VAT is often expressed as a percentage of total time.
- First Pass Yield (FPY) – This represents the percentage of time that all activities within a process step are correctly completed on the first attempt. It includes both the value-added activities and non-value activities. If a step operator (or anyone else) must rework an item, even if it is done as part of the step, then that item is not counted as a successful first pass attempt.
Although not a metric, this module includes an illustration of the Swim Lane mapping technique. This map shows the As-Is flow of process steps through the different organizations or departments responsible for completing a step.
Each Swim Lane in the map represents an organization or department. The process steps are placed in the lane for the organization or department responsible for completing the step. The steps are then connected in the correct “as-is” process sequence. The Swim Lane chart shows when the process flow crosses organization or department boundaries. Every time the process crosses into a new lane, there is a higher probability for delays and errors due to the required handoff.
Hints & tips
- Time is added, yield is multiplied.
- That VAT as a percent of ToT is often low single digits.
- The FPY is often less than 50% when a step requires “tweaking” by an operator.
- The handoffs across lanes as shown in the Swim Lane chart are more likely to have problems than handoffs within a lane. This is due to different organizations having different priorities and the increased likelihood that critical details are lost or misunderstood during the handoff.
Lesson notes are only available for subscribers.