Descriptive Statistics You are a manufacturing engineer managing a vertical mill

Question

Descriptive Statistics You are a manufacturing engineer managing a vertical milling process, lire parts are milled on 4 different CNC vertical machining centers. Prior to your employment with the company, the management purchased each machine solely on the basis of cost. You are recommending the purchase of an additional vertical machining center but you are interested in getting fastest eye c time or cost. The CNC machine will be dedicated to a single part and therefore cycle time is the most important characteristic. The specifications (HP. work envelope, spindle RPM) for the machine identical. You decide to gather some data. The data is based upon cycle time while remaining within tolerance. You suspect that some of the machines are not rigid enough to operate at high speed without deflection and the setup time will differ with each machine but are unable to support your claim. Determine which machine should be purchased and defend your answer with an analysis of the data and appropriate graph.

Explanation / Answer

Mean Cycle time for Machine 1 = 13.52 s

Standard Deviation of Cycle time for Machine 1 = 0.893682 s

Mean Cycle time for Machine 2 =13.41 s

Standard Deviation of Cycle time for Machine 2 = 1.455 s

Mean Cycle time for Machine 3 = 13.41 s

Standard Deviation of Cycle time for Machine 3 = 0.769 s

Mean Cycle time for Machine 4 = 12.86 s

Standard Deviation of Cycle time for Machine 4 = 0.9488 s

Lowest Average Cycle time is for Machine 4 which costs $73K

Second Lowest Average Cycle time is for Machine 3 which costs $80K

Standard Deviation of Cycle time for Machine 4 is slightly greater than machine 3 but machine 3 costs $7K (approx 10%) more than machine 4.

Therefore a good choice will be Machine 4, it has the best average cycle time and a standard deviation better than Machine 1 and Machine 2.

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---