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Field Book · Chapter 2 of 8 · Red tag and quality alert

Contain It

Everything made since the last good check is suspect. How to count the window, find every piece, red tag it and send the quality alert before you sort.

By Chris Martin, quality manager. 2 minute read. Free, no signup.

Start the containment fence at the last good check, not the first bad reading. Count what the machine made in that window (here 190 minutes at 36 an hour, 114 pieces), find every piece until the count matches, red tag and log each location, and send a quality alert downstream. Do not sort until the gage is trusted.

The operator calls the shift lead. At 12:10 the lead stops Lathe 3. The last check that was good, with a reading in the normal range, was at 9:00: 24.006. Everything made since 9:00 is suspect.

That is 190 minutes at 36 pieces an hour, or 114 pieces. Containment answers one question: where are they?

Start the fence at the last good check

Do not start at the first bad reading. The drift began before anyone saw it. The last time you know the process was good is the edge of the fence, and everything after it is in until a trusted check says otherwise.

The lead and the operator found all 114:

  1. Two bins at the cell, 38 pieces each, so 76.
  2. One tote at the wash station, 38 pieces.
  3. Nothing at final inspection or in shipping. Both were checked, and both were empty of this window.

76 plus 38 is 114. If your count does not match the production count for the window, keep looking before you tag.

Tag it, log it, tell the floor

Red tag every bin and tote. Write one line on the red tag log for each: tag number, the window, the location and the reason. Then send a quality alert to the wash station, final inspection, shipping, the next shift lead and maintenance. The alert says what the part is, what you suspect, which pieces, and what to do if you find some.

Do not sort yet. A sort with a gage nobody has checked is another guess. That comes next.

Read more: how to quarantine and red tag nonconforming material.

The mistake to avoid

Tagging only what you can see at the machine. Parts move. By the time someone calls the lead, part of the window is already downstream.

ON THE FLOOR MONDAY
  • Name the last good check for one process, and what you would count from it.
  • Check every cell has red tags and a marked hold spot.
  • Write down who can stop a machine and call a fence.

Open the printable Monday Board

Want every tool on this trail in one purchase? The Process Trail Bundle has all 13.

The part, the machine, the shift and every number in this book (shaft SH-3306 on Lathe 3) are a made-up example. The tool sidebars show ShopFloorOps tools, which I make and sell. Every chapter teaches the step itself, so you can use your own forms. New to a term? See the quality glossary.