Quality
Quality tests whether you can distinguish prevention from inspection, apply a recognised improvement framework, and find root cause instead of blame.
Assurance versus control
Quality assurance designs the process so defects do not occur: procedures, specifications, training, audits. Quality control measures output: inspections, checklists, SLA sampling. A checklist is control; the procedure that made the checklist necessary is assurance.
Frameworks
A quality management system in the ISO 9001 model rests on process approach, documented information, risk-based thinking, customer focus, and continual improvement. Six Sigma's DMAIC cycle (Define, Measure, Analyse, Improve, Control) targets variation. Lean removes waste; 5S imposes workplace discipline; PDCA underlies most improvement cycles. Root cause tools are 5 Whys and the fishbone, covering people, process, equipment, materials, environment, and measurement.
Worked example
A janitorial SLA requires 95% of areas to pass monthly inspection. The month returns 92%, with failures concentrated on one building's third floor, all on the evening shift. Retraining everyone is the reflex; the actual finding is that the evening crew's supply closet was relocated, adding twelve minutes per round. Fix the logistics, then re-measure. The reasoning shown is: stratify the data first, then investigate the specific stratum, then verify by re-measurement.
Measurement discipline
Define the standard, the sampling method, and the acceptance rule before measuring. Read trend, not a single month. Normalise complaint data, for example complaints per 1,000 occupants, so comparison is meaningful.
Traps
- Confusing assurance with control.
- Inspecting harder when the process itself is the cause.
- Changing the measurement method mid-year.
- Treating a satisfaction score as if it were an SLA.