Reference no: EM133413408
Statistical Process Control and Improvement
Problem #1 (Attribute Control Chart):
Part (a): The data in the companion data table represent the results of inspecting all units of a personal computer produced for the past ten days. Does the process appear to be in control? Please use the Excel data table provided on this class website.
ISE131-Problem#1-data-table-PC inspection
Part (b): Construct a standardized control chart for the data of Part (a)
Problem #2 (Attribute Control Chart): Surface defects have been counted on 25 rectangular steel plates, and the data are shown in the companion data table. Set up a control chart for nonconformities using these data. Does the process producing the plates appear to be in statistical control?
Please use the Excel data table provided on this class website. ISE131-Problem#2-data-table-surface defects
Problem #3: Suppose that a single-sampling plan with n = 150 and c = 2 is being used for receiving inspection where the supplier ships the product in lots of size N = 3,000. Do all three parts with Excel.
(a) Draw the OC curve for this plan.
(b) Draw the AOQ curve and find the AOQL.
(c) Draw the ATI curve for this plan.
Problem #4: Suppose that a supplier ships components in lots of size 5,000. A single- sampling plan with n = 50 and c = 2 is being used for receiving inspection. Rejected lots are screened, and all defective items are reworked and returned to the lot. Do all five parts with Excel.
(a) Draw the OC curve for this plan.
(b) Find the level of lot quality that will be rejected 90% of the time.
(c) Management has objected to the use of the above sampling procedure and wants to use a plan with an acceptance number c = 0, arguing that this is more consistent with their Zero Defects program. What do you think of this?
(d) Design a single-sampling plan with c = 0 that will give a 0.90 probability of rejection of lots having the quality level found in part (b). Note that the two plans are now matched at the LTPD point. Draw the OC curve for this plan and compare it to the one for n = 50, c
= 2 in part (a).
(e) Suppose that incoming lots are 0.5% nonconforming. What is the probability of rejecting these lots under both plans? Calculate the ATI at this point for both plans. Which plan do you prefer? Why?
Attachment:- Statistical Process Control.rar