1. Problem Recognition
Car tyres factory is designed to produce 900 tyre per day. Although the number of tyres rejected by quality control section due to manufacturing defect are recorded in daily production for a month of August around 340 tyres. The QC department wants to draw a control chart to present the values to management. After that the management can take action to purchase tyres recycling machine. And determine the machine capacity that will be purchased.
2. Development the Feasible Alternative
Quality control department recorded the items rejected for the month of August 2014. Control chart will be presented to management for the quantity rejected in a month in order to support their proposal to purchase recycling machine.
3. Development of the Outcome for Alternative
The quantity rejected recorded in table-1. The mean and Upper/Lower Control Limit are calculated as well.
4. Selection of Criteria
Recycling machine capacity will be purchase based on the upper control limit calculated for a month.
5. Analysis and Comparison of the Alternatives
The Run chart (control chart) was generated from the data collected in daily production report and shown below in Figure-1. The upper control limit calculated to be 22 Items for a month.
6. Selection of the Preferred Alternative
It can be observed from control chart that the average items rejected is 12 items per day and between 22-1 items for a month. The recycling machine which will be purchased should have a capacity to recycle 22 tyers per day.
7. Performance Monitoring and the Post Evaluation of Result
Production department will monitor the daily production and will initiate return on investment report for recycling machine.
- Bassard, Michael & Riter, Diane (2010). The Memory Jogger 2nd Edition, Canada, GOAL/QPC
- A Guide to Control Charts, retrieved on 8th of August2014 http://www.isixsigma.com/tools-templates/control-charts/a-guide-to-control-charts/
- What are Variables Control Charts?, retrieved on 8th of August2014 http://www.itl.nist.gov/div898/handbook/pmc/section3/pmc32.htm