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164 Part III: Inspection and Test
Part III.C.1
• Inspect the first few units of each new batch in order to verify that the
setup is correct.
The basic tool for choosing the location of inspection stations is the flowchart. The
most typical locations are (Gryna 2001):
• At receipt of goods from suppliers, usually called incoming inspection or
supplier inspection.
• Following the setup of a process, to provide added assurance against
producing a defective batch. In some cases this “setup approval” also
becomes approval of the batch.
• During the running of critical or costly operations, usually called
process inspection.
• Prior to delivery of goods from one department to another, usually
called lot approval or tollgate inspection.
• Prior to shipping completed products to storage or customers, usually
called finished-goods inspection.
• Before performing a costly, irreversible operation, for example,
pouring a melt of steel.
• At natural “peepholes” in the process.
A flowchart example is shown in Figure 16.2.
Incoming Material Inspection
Incoming material inspection is performed when materials or supplies are purchased
from one company by another. This is considered a producer–supplier
relationship, where the acceptance or rejection decisions of submitted lots are
based on a certain criterion agreed upon between both companies. The purpose
of incoming inspection is to distinguish between good lots and bad lots. The decision
that follows an incoming inspection procedure falls into one of the following
categories:
1. Accept the lot, that is, the lot conforms to specifications.
2. Reject the lot, that is, the lot is considered nonconforming.
3. The lot must go to a screening inspection (100% inspection).
First-Piece Inspection
In this case, the inspection is more likely to be carried out by the operator. The
purpose is to make sure that all procedures and execution of work is properly
employed according to specified work standards or specifications.