STATISTICAL THINKING IN PROBLEM-SOLVING

State-of-the-art problem-solving methodologies include trend charts (o r run charts) and Pareto analyses. A trend or run chart represents dat a in its time sequence. The user of a trend chart typically looks for trends the data from time to time, such as gradual improvement or dete rioration. The user also looks for spikes and dips in the data to iden tify any sudden performance changes. An inherent problem with using tr end charts that the data is treated as if it is deterministic. Failing to understand that each data point represents one realization of a ra ndom number leads incorrect conclusions. Actions based on these conclu sions increase variation in the process and cause more product failure s.