DMAIC: Measure Phase
Measurement helps LSS succeed when other approaches fail. Without data, projects can become short-lived or provide disappointing results.
In this DMAIC phase, we need to establish an accurate baseline measurement to determine project improvements. Identifying process constraints is key.
Measure Phase Deliverables may include:
- Identify the key process output variable – “Y”
- Calculate total Process Lead Time
- Develop Data Collection Plan
- Perform Measurement System Analysis
- Develop Control Charts
- Determine Process Capability
- Establish Measurement Baseline
- Identify Quick Improvement opportunities
Measure Phase Tools
Purpose: A Value Stream Map shows the materials and information flow along with detailed process information. The goal for the project illustrated in our sample map is to improve lead time. This map (see page 42) highlights areas in which operations can be sped up and potential areas where waste exists in the process.
Application: Used during the Measure Phase of a project to help us understand the current state of the process and the source of waste.
• Provides understanding of how the current process works
• Communication of the current process
• Highlights inefficiencies and waste
• Reference document for the team and for discussion
• Highlights possible quick wins for process improvements
Measurement System Analysis (MSA)
Purpose: This is a statistical technique used to determine the ability of a measurement system to measure a process precisely and accurately.
Two sources of variation can occur when measuring process output: part-to-part variation and measurement system variation.
If measurement system variation is large compared to the part-to-part variation, few conclusions can be drawn.
Application: First, validate the accuracy of the measurement system against a known standard (if available). Second, validate the precision and discrimination of the measurement system with a Gauge Repeatability and Reproducability study. If the measurement system is not capable, the baseline data may be misleading. After passing MSA, process control and capability can now be used to determine the stability and capability of the process.