Statistical tools for quality diagnosis: A case study in the meat product industry

Diagnosis is a methodological management strategy used to solve tolerance problems and to identify the causes of deviations or defects. Some quality tools (histograms, Ishikawa diagrams, Pareto diagrams, maintenance failure mode effects analysis; FMEA) were applied as a diagnostic strategy at a canned meat enterprise (CME) with net weight problems. The results showed that an average of 75% of the biggest quality problems due to internal defects are caused by low weight, equivalent to a 0.55% defective production with regard to the total production. Of the observations made, 58% were outside specifications; which leads to a real capacity process of 0.004. The low weight problems in a CME are caused in an 80% by the following problems: time-temperature ratio of the mixture, vapor amount, floor plan of the work place, velocity (rpm) and design of the mixing blades, and vapor quality. The most critical components and processes are: time-temperature ratio of the mixture, high and low velocity and design of the mixing blades, vapor control valves and calibration of the heating equipment in the control of the mixing machines; these represent 80% of the fault modes. The quality control system of a CME should include an improvement program based on reduction of the inherent process variability by 83%, displacing the population mean to the left by 98%.