Process capability analysis of sand casting of flange roller: A case study of Akaki basic metals industry

Abstract

Process Capability Analysis Is A Technique Used To Identify The Natural Variability Of The Process And To Check How Much Product Is Falling Beyond The Specifications. Akaki Basic Metals Industry Had A Wide Spectrum Of Products Delivered To The Customer On Demand. They Have Variety Of Manufacturing Process To Suit The Requirements For Finished Products But Still Have Some Issues Related To Quality And Problem Related To Process In-Capability In Machines And Methods. There Is Also A Rejection Due To Poor Quality, Dimensional Variation And Geometrical Tolerance Of The Products. The Purpose Of This Study Is To Investigate The Root Causes Of Dimensional Variation Of The Products And To Improve Quality By Suggesting Directions For Improvement. The Case Study Research Was Based Up On The Primary Data Collected From Abmi Sand Casting Process. To Perform Capability Analysis, The Collected Data Has Been Checked For Normality And The Process Has To Exhibit Control. For 20 Subgroup Of Sample Size 5 Statistical Software Minitab 17 Was Used To Prepare Control Chart, Frequency Histogram And Probability Plot And For Calculation Of The Potential And Overall Capability Indices. The Analysis Indicates That Though The Process Is Centered, The Process Is Not Capable To Manufacture Flange Roller With The Customer Specification Limits Since The Values Of Capability Indices Are Less Than The Desired Value 1.33. During Brainstorming Session The Root Causes Of Dimensional Variation Are Identified From Method, Materials, Machine And Man Power And The Ishikawa Diagram Was Created And Corrective Action Has Been Provided For The Improvement Of The Process.