What is the definition of tampering in a quality process?

Tampering in a quality process refers to making minor adjustments based on perceived variations. This behavior often leads to a cycle of unnecessary changes that can destabilize a process rather than improve it. When individuals react to natural variations—those inherent in any process—by adjusting parameters or methods, they may inadvertently introduce new sources of variation, creating more inconsistencies rather than stabilizing the process.

For example, if a production line is consistently producing items that occasionally fall slightly below a target specification, a team member might adjust the machinery settings to correct what they perceive as an issue. However, if the variations are within acceptable limits of natural fluctuation, this minor adjustment may cause more problems than it solves by disrupting a stable process.

Understanding this behavior is critical in quality improvement, as it highlights the importance of data analysis and process stability. When teams are well-trained in quality principles and understand the difference between common cause (natural variation) and special cause variation (indicating a problem), they can make more informed decisions that lead to true improvements rather than misguided tampering.