Question
Stooge Enterprises (Stooges) manufactures wooden mallets for commercial and residential applications. Stooges landed a major contract as a supplier to Slapsticks, Inc., a leading retailer
Stooge Enterprises (Stooges) manufactures wooden mallets for commercial and residential applications. Stooges landed a major contract as a supplier to Slapsticks, Inc., a leading retailer in several major cities throughout the upper Midwest. Because of the large volume of demand, Stooges has to expand its manufacturing operation to three shifts and hire additional workers.
Not long after Stooges began mallets to Slapsticks, it began receiving some complaints about mallet head diameters. This problem was somewhat alarming to Stooges, because its reputation as a high quality manufacturer was the principal reason that it was selected as a supplier to Slapsticks. Stooges placed a great deal of confidence in its manufacturing capability because of its well trained and dedicated employees, and it never felt the need to consider formal process control approaches. In view of the recent complaints, the company president suspected that the expansion to a three-shift operation and the pressures to produce higher volumes and meet just-in-time delivery requests was causing a breakdown in their quality.
On the recommendation of the plant manager, Stooges hired a recent College of Saint Rose graduate to train the shift supervisors and selected line workers in statistical process control methods. As a trial project, the plant manager wants to evaluate the capability of a critical cutting operation that he suspects might be the source of the diameter problem. The nominal specification for the diameter operation is 8.27 inches with a tolerance of plus or minus 0.05 inches. The consultant suggested inspecting five consecutive mallet heads in the middle of each shift over a 10-day period and recording the dimension of the cut. The table that follows shows 10 days data collected for each shift. The data is a file named STOOGE DATA.XLS.
Questions
Interpret the data, establish a state of statistical control, and evaluate the capability of the process to meet the specifications. Consider the following questions:
What do the initial control charts tell you?
If the process is not in control, what might be the likely causes? Take corrective action based on the information that is available and re-evaluate the process.
Evaluate the capability of the process to meet the specifications. Consider the following questions:
What is the process capability?
What does the process capability tell the company?
If 10,000 mallets are selected at random, how many are expected to not meet the customer specification?
| | | | Observations | ||||
| Sample | Shift | Operator | 1 | 2 | 3 | 4 | 5 |
| 1 | 1 | Moe | 8.262 | 8.245 | 8.257 | 8.247 | 8.241 |
| 2 | 2 | Curly | 8.243 | 8.242 | 8.241 | 8.236 | 8.257 |
| 3 | 3 | Larry | 8.262 | 8.251 | 8.257 | 8.247 | 8.257 |
| 4 | 1 | Moe | 8.250 | 8.250 | 8.245 | 8.250 | 8.259 |
| 5 | 2 | Shemp | 8.213 | 8.245 | 8.241 | 8.224 | 8.219 |
| 6 | 3 | Curly | 8.255 | 8.248 | 8.248 | 8.252 | 8.264 |
| 7 | 1 | Larry | 8.244 | 8.248 | 8.247 | 8.248 | 8.251 |
| 8 | 2 | Moe | 8.248 | 8.238 | 8.236 | 8.253 | 8.246 |
| 9 | 3 | Curly | 8.243 | 8.250 | 8.242 | 8.244 | 8.244 |
| 10 | 1 | Moe | 8.261 | 8.244 | 8.256 | 8.249 | 8.261 |
| 11 | 2 | Curly | 8.257 | 8.250 | 8.256 | 8.236 | 8.250 |
| 12 | 3 | Larry | 8.239 | 8.246 | 8.245 | 8.252 | 8.259 |
| 13 | 1 | Moe | 8.260 | 8.242 | 8.251 | 8.244 | 8.243 |
| 14 | 2 | Curly | 8.252 | 8.256 | 8.247 | 8.238 | 8.249 |
| 15 | 3 | Larry | 8.245 | 8.252 | 8.250 | 8.261 | 8.250 |
| 16 | 1 | Moe | 8.269 | 8.250 | 8.257 | 8.247 | 8.253 |
| 17 | 2 | Curly | 8.249 | 8.242 | 8.249 | 8.260 | 8.244 |
| 18 | 3 | Larry | 8.249 | 8.246 | 8.250 | 8.260 | 8.255 |
| 19 | 1 | Moe | 8.245 | 8.254 | 8.261 | 8.251 | 8.241 |
| 20 | 2 | Curly | 8.256 | 8.262 | 8.260 | 8.247 | 8.252 |
| 21 | 3 | Shemp | 8.220 | 8.221 | 8.248 | 8.243 | 8.239 |
| 22 | 1 | Moe | 8.261 | 8.256 | 8.241 | 8.249 | 8.252 |
| 23 | 2 | Curly | 8.267 | 8.253 | 8.256 | 8.256 | 8.260 |
| 24 | 3 | Shemp | 8.225 | 8.219 | 8.245 | 8.220 | 8.220 |
| 25 | 1 | Moe | 8.258 | 8.253 | 8.255 | 8.250 | 8.250 |
| 26 | 2 | Curly | 8.262 | 8.252 | 8.260 | 8.248 | 8.243 |
| 27 | 3 | Larry | 8.249 | 8.248 | 8.246 | 8.256 | 8.253 |
| 28 | 1 | Moe | 8.265 | 8.258 | 8.245 | 8.257 | 8.259 |
| 29 | 2 | Curly |
Step by Step Solution
★★★★★
3.49 Rating (149 Votes ) There are 3 Steps involved in it Step: 1Initial control charts indicate the average of 8248 which indicates most values lying on on the lowe...
Get Instant Access to Expert-Tailored SolutionsSee step-by-step solutions with expert insights and AI powered tools for academic success Step: 2
Step: 3
Ace Your Homework with AIGet the answers you need in no time with our AI-driven, step-by-step assistance Get Started
Business Statistics A Decision Making ApproachAuthors: David F. Groebner, Patrick W. Shannon, Phillip C. Fry 9th Edition 013302184X, 978-0133021844 | ||||
