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172 Part III: Inspection and Test
The use of a tracing code (Feigenbaum 1991) is required for efficient operations.
This code is established at the beginning of material flow and a traceability
flowchart is established.
The major activities in the flowchart include:
1. Critical component selection and listing by part number.
2. Vendor part coding (recording vendor name and date of receipt).
3. Coding internally manufactured parts, subassembly, assembly, and
storage in a daily tally. At the end of the assembly line, each shipping
container is date coded. This sequential coding procedure provides
sufficient data to tie critical components to specific dates of receiving
inspection, manufacturing, and final assembly.
4. Computerized shipping records, including date codes, customer name,
and destination. Correlation of these data with tracing code numbers
results in very effective traceability of critical components.
Identification of Materials
Part III.C.3
The only reason to identify anything is to be able to trace it. And the only reason
to trace it is to be able to find out something about it later. But those are two huge
reasons in today’s highly technological and litigious society. Without product
traceability, many manufacturers would be exposed to unacceptable risk.
Principles of Identification. Modern technology has produced a wide array of
identification methods. The physical application of markings and subsequent
tracking by means of scanners and sensors provides many options. It is necessary
to maintain records not only of items produced and their identification but also
of how the record-keeping system itself is operated and modified. After all, the
storage and retrieval of information is a rapidly changing field.
Mechanics. To illustrate the mechanics of product identification, consider the case
of the Sauer Danfoss Company in Ames, Iowa. This company makes moderately
complex mechanical products that require 100 percent testing and periodic design
modifications. They have recently improved their materials management system
by creating a multifunctional task team of four people. The team collected data for
two and one-half years and finally decided to scrap their existing system for tracking
material, which was dependent on manual entry into paper “move tags” and
then manual keying into a computer database. Determination of current status
required frequent physical counting of all items.
The team started over completely with bar code and RFID (radio frequency
identification) technologies. Now whenever an item of hardware moves, it is
automatically accounted for, either by a bar code scanner or an RFID receiver. A
sophisticated database system automatically processes each scan. The database
maintains a variety of characteristics about each unit, including:
• Model number