Question

Precise Equipment Manufacturing (PEM) is an engineering company that specialises in motor components. PEM have asked a subcontractor to produce a number of steel rods. However, a prerequisite for the contract is that the subcontractor can prove that their processes are capable of meeting the customer-defined specifications. The specifications for the rods stipulate that the nominal length for a rod is 450.00 cm with an upper specification limit of 450.12 cm and a lower specification limit of 449.88 cm. The subcontractor who wants to produce the rods for PEM has a machine that can produce rods where the length follows a normal distribution, with a mean of 450.05 cm and a standard deviation of 0.03 cm.

(a) Calculate the subcontractor’s process capability ratio Cp.

(b) Calculate the subcontractor’s process capability index Cpk.

(c) Determine if the subcontractor, given the current component specifications and with the current machine conditions, can satisfactorily produce the rods for PEM. Explain why or why not.

(d) The subcontractor managed to make the mean length 450.00 cm. What maximum standard deviation would the machine need to maintain in order to achieve 6-sigma quality (so that the capability index is equal to 2)?

Answer 1

Due to insufficient time , i will not answer(c) bit .

please send the separate question , i will answer it .

Thank you!