The Traffic Cop: A Graphical Example

The Traffic Cop’ goal is to monitor and manage starts, to control equipment utilization. What the Traffic Cop does is:

Identify the fab bottleneck with a capacity model (usually spreadsheet, queueing, or simulation-based).

Control fab starts to keep the bottleneck utilization below 85%.

Monitor performance measures in the fab (especially WIP turns) to avoid unexpected utilization spikes

Regular Monitoring

On a daily basis, the Traffic Cop monitors fab performance through a series of summary charts (or dashboard charts). These typically include things like: starts, moves, turns, WIP trend, throughput, cycle time, and scrap charts. Click here to see sample Traffic Cop dashboard charts. We have observed that maintaining a set of dashboard charts such as this one helps people using the Traffic Cop style to be successful. The reason for this is that the Traffic Cop encourages other people in the fab to watch the same dashboard, and thus ensures that problems are noticed immediately, rather than after the fact.

In-Depth Analysis

When specific problems come up, the Traffic Cop performs more in-depth analysis, to understand root causes. This type of analysis is illustrated with a five-part example, broken into the following sections:

1. Early Warning Indicators
2. Other Performance Measures (Confirmation)
3. Finding the Problem Tool Group
4. Root Cause Analysis
5. Consequences and Corrections

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