SMU MBA ASSIGNMENTS

QM0012- Statistical Process Control and Process Capability

QM0012- Statistical Process Control and Process Capability

Summer 2013

QM0012- Statistical Process Control and Process Capability

Q1. a. What is Statistical Process Control? Distinguish between Statistical Quality Control and Statistical Process Control.

(Meaning — 2 marks, Differences — 3 marks)

Answer :  Statistical Process Control :

Statistical process control (SPC) is a method of quality control which uses statistical methods. SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or trash). SPC can be applied to any process where the “conforming product” (product meeting specifications) output can be measured.

Q2. a. Explain the Cause and Effect diagram.

(Explanation — 5 marks)

Answer : Cause and Effect diagram :

Cause and Effect Diagram, also called as “fish bone diagram” or “Ishikawa diagram”, shows relationships between events and is a useful analysis in generating ideas and in identifying the root cause of problem. It is used to brainstorm out possible contributing causes of a particular problem or defect. The cause & effect diagram is the brainchild of Kaoru Ishikawa, who pioneered quality management processes in the Kawasakishipyards and in the process, became one of the founding fathers of modern management.

Q3. Explain the structure and construction of Control Charts. Explain with an example how to construct X-bar Chart and R Chart.

(Structure — 3 marks, Construction — 3 marks, Examples — 4 marks) 10 marks

A control chart is a graphical representation of the collected information. The information may pertain to measured quality characteristics or judged quality characteristics of samples. It detects the variation in processing and warns if there is any departure from the specified tolerance limits.

Structure of control charts :

Q4. What is the meaning of experimental design? Explain the guidelines for designing experiments.

(Meaning — 3 marks, Guidelines — 7 marks) 10 marks

In experimentation we attempt to monitor the effects of certain inputs or material on the subject matter, of interest. The inputs could be different hedgerow leguminous plants planted under identical conditions, while the effects to be monitored could be the changes in soil fertility status, the yield of agricultural crops planted between the rows, the productivity of the animal being fed with the foliage from the tree crops, or the tree crop performance.

Q5. Explain the concept of Process Capability. Distinguish between Process Stability and Capability. Mention the major uses of Process Capability.

(Explanation — 4 marks, Differences — 3 marks, Uses — 3)

A process is a unique combination of tools, materials, methods, and people engaged in producing a measurable output; for example a manufacturing line for machine parts. All processes have inherent statistical variability which can be evaluated by statistical methods. The Process Capability is a measurable property of a process to the specification, expressed as a process capability index (e.g., Cpk or Cpm) or as a process performance index (e.g., Ppk or Ppm

Q6. What is Acceptance sampling? Explain the guidelines for using Acceptance Sampling.

(Meaning — 4 marks, Guidelines — 6 marks) 10 marks