DWC cheat sheet

Governing document hierarchy runs statute → regulation → adopted standard → contract specification; a lower tier may never relax a requirement imposed by a higher tier.

Verification confirms that specified requirements were met (built correctly); validation confirms the item serves its intended use under actual operating conditions (built the right thing).

Quality assurance is process-focused and preventive; quality control is product-focused and detective, relying on inspection, test, and measurement.

Risk score = likelihood × consequence; residual risk is the risk remaining after controls are applied and must be compared against the documented acceptability criterion.

Corrective action removes the cause of a detected nonconformity to prevent recurrence; preventive action removes the cause of a potential nonconformity before it occurs.

Normative language: 'shall' indicates a mandatory requirement, 'should' a recommendation, and 'may' a permissible option; only 'shall' statements are auditable obligations.

Traceability chain runs requirement → design element → realisation step → verification evidence → retained record; any break in the chain is a documentation nonconformity.

Conformance means meeting a specified requirement; compliance means meeting an external legal or regulatory obligation - the two are assessed against different references.

A well-formed requirement is singular, unambiguous, verifiable, and traceable; SMART framing (Specific, Measurable, Achievable, Relevant, Time-bound) is the common test.

Requirement classes to capture separately: functional, non-functional/performance, interface, environmental, and regulatory; each needs its own verification method (inspection, analysis, demonstration, test).

The 100% rule for a work breakdown structure states that the sum of child elements must capture exactly all of the parent's scope - no more and no less.

Critical path is the longest duration path through the network and sets the minimum project duration; activities on it have zero total float.

Total float = Late Start − Early Start = Late Finish − Early Finish; float is the time an activity can slip without delaying the project finish date.

A baseline is the approved, version-controlled reference for scope, schedule, or cost and may be changed only through the formal change control process.

Design reviews are gated: exit criteria must be met and recorded before the design is released to the next phase (for example preliminary review before detailed design, critical review before build).

A risk register entry records cause, risk event, effect, probability, impact, owner, and planned response; a risk without a named owner is not a controlled risk.

PDCA: Plan (set objectives and process), Do (implement), Check (monitor and measure against objectives), Act (improve and re-standardise) - repeated as the improvement loop.

Change control evaluates each request for impact on scope, schedule, cost, risk, and compliance; only approved changes authorise revision of the baseline.

Process capability Cp = (USL − LSL) / 6σ measures spread only; Cpk = min(USL − μ, μ − LSL) / 3σ also accounts for off-centre mean and is always ≤ Cp.

Control charts separate common-cause variation (inherent, requires process change) from special-cause variation (assignable, requires investigation of that occurrence).

RACI assigns Responsible (does the work), Accountable (owns the outcome, exactly one per activity), Consulted (two-way input), Informed (one-way update).

Leading indicators predict future performance (training completion, open corrective actions); lagging indicators report outcomes already realised (incidents, defect rate).

Handover readiness requires completion of the punch list, verified as-built documentation, training records, spares and warranty data, and signed operational acceptance.

Hierarchy of controls in descending effectiveness: elimination, substitution, engineering controls, administrative controls, then personal protective equipment as the last line.

Energy isolation for maintenance follows lockout/tagout: isolate, lock, tag, release stored energy, verify zero energy state, and restore only after controlled removal.

Incident classification distinguishes near miss (no harm or damage but real potential), first-aid case, and recordable case; each class carries its own notification threshold and timeline.

ALARP requires risk to be reduced as low as reasonably practicable, weighing further control cost against the magnitude of risk reduction achieved.

A permit-to-work is a documented authorisation for a defined high-hazard task, valid for a stated location and time, with specified precautions and sign-off.

A compliance obligations register lists each legal or regulatory obligation with its source, accountable owner, evidence of fulfilment, and scheduled review date.

Audit findings are graded (for example major or minor nonconformity, or observation); closure requires root cause analysis plus verified corrective action, not just a stated fix.

Controlled documents carry a unique identifier, revision status, approval signature, effective date, and defined distribution; superseded versions are withdrawn from use.

Documents describe what should be done and are revised; records are evidence that it was done and are never altered after the fact.

Nonconformance disposition options are use-as-is (concession), rework, repair, reclassify, or reject/scrap - each requires authorised approval and recorded justification.

Inspection and test plans use hold points (work cannot proceed without documented approval), witness points (notification and right to attend), and review points (records only).

Root cause analysis tools include 5 Whys for a single causal chain and cause-and-effect (fishbone) diagrams grouped by the 6M categories: man, machine, material, method, measurement, environment.

Data integrity follows ALCOA: Attributable, Legible, Contemporaneous, Original, Accurate - plus complete, consistent, and enduring for retained records.

A technical report contains purpose, scope, method, results with stated uncertainty, findings, conclusion, and recommendations, with raw data referenced as an appendix.

Measurement equipment must be within its calibration interval and traceable to a recognised reference standard before its readings are accepted as verification evidence.