# Question: An automobile manufacturer wishes to control the number of nonconformities

An automobile manufacturer wishes to control the number of nonconformities in a subassembly area producing manual transmissions. The inspection unit is defined as four transmissions, and data from 16 samples (each of size 4) are shown in Table 7E.16.

(a) Set up a control chart for nonconformities per unit.

(b) Do these data come from a controlled process? If not, assume that assignable causes can be found for all out-of-control points and calculate the revised control chart parameters.

(c) Suppose the inspection unit is redefined as eight transmissions. Design an appropriate control chart for monitoring future production.

(a) Set up a control chart for nonconformities per unit.

(b) Do these data come from a controlled process? If not, assume that assignable causes can be found for all out-of-control points and calculate the revised control chart parameters.

(c) Suppose the inspection unit is redefined as eight transmissions. Design an appropriate control chart for monitoring future production.

## Answer to relevant Questions

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