APQP: the five phases and what each one delivers

What APQP is

Advanced product quality planning is a structured method for developing a product and the process that will make it. It starts with the customer's needs and ends with a launched part, a stable process and a record of what should change next time.

The method has five phases and a set of gate reviews. The phases are not a waterfall. Design and process work overlap, and a supplier may be buying tooling while the drawing is still moving. The discipline is in the outputs: each phase has to produce something the next phase can use.

Phase 1: plan and define the programme

The first phase turns a request into a programme. The team collects the customer's needs, the business case, benchmark data, reliability targets and any regulatory requirement. It builds a preliminary bill of material, a preliminary process flow and a product assurance plan.

The output is a set of design and quality goals with an owner and a date. The gate question is simple: is the programme defined, resourced and worth doing? A team that cannot answer that question will spend the rest of the project solving it in the tooling budget.

Phase 2: product design and development

The second phase makes the design real. The team completes the design FMEA, checks design for manufacturability and assembly, plans the design verification, builds prototypes and releases the drawings, specifications and material calls.

The output is a design that has been tested against its own verification plan. The gate question is whether the design meets the requirements, not whether the drawing looks finished. A drawing released before the verification results are reviewed is a schedule decision, not an engineering one.

The prototype is a learning tool, not the production part. Build it with the intended material and process where possible, measure it against the verification plan and record every deviation. A prototype made by hand can still prove a concept, but it cannot prove a production process.

Phase 3: process design and development

The third phase designs the manufacturing system. The team writes the process flow, the process FMEA and the control plan, then specifies the tooling, the gauges, the work instructions, the packaging and the operator training.

This is where the quality of the launch is decided. The flow diagram sets the steps. The PFMEA sets the risks and the actions. The control plan sets the controls, the sample size and the reaction plan. If those three documents are written by three people who never meet, the production line will show it.

The gate question is whether the process is ready to validate. That means the tooling is in place, the gauges are studied, the operators are trained and the control plan describes the process that will actually run.

Phase 4: product and process validation

The fourth phase runs the process and proves it. The team completes a significant production run, studies the measurement systems, calculates initial process capability, runs the production validation tests and evaluates the packaging.

The output is a production control plan and a submission pack, usually a PPAP. The gate question is whether the process makes conforming parts at the quoted rate, with the production tool, the production operators and the production material. A run that needed an engineer at every station has not answered that question.

Run at rate is the practical test. The line should make the quoted volume, with the quoted labour and the quoted cycle time, while the control plan is followed. If the run needs extra inspection or a slower cycle, the process is not validated yet, even when the parts are good.

Phase 5: feedback and corrective action

The fifth phase starts at launch and does not really end. The team watches variation, delivery and service performance, reduces the largest losses and records the lessons that should change the next programme.

The gate question is what the organisation will do differently. A lessons learned document that nobody reads is not an output. A change to the design guide, the PFMEA library or the supplier selection criteria is.

The gates and the timing

APQP is often drawn as five boxes in a row. In practice, phases overlap and the gate reviews are where the overlap is controlled. Each gate should have a named reviewer, a date and a decision: proceed, proceed with actions, or stop.

The table gives the main output and the exit question for each phase. Use it as a checklist, not as a substitute for the customer's own programme requirements.

Keep the gate record short. The date, the attendees, the documents reviewed, the open actions and the decision are enough. The value is in the decision and the follow up, not in the length of the minutes.

Where APQP goes wrong

The most common failure is starting phase three before the design is fixed. Tooling is ordered against a drawing that later changes, and the process validation is repeated on a new tool. The schedule loses more time than the design review would have taken.

The second failure is copying documents. A PFMEA from a similar part is a useful starting point, but it is not an analysis of this part. A control plan written for the auditor, rather than for the operator, will not control anything on the line.

The third failure is treating the gate as a meeting. A gate without a decision, an action list and a named owner is a status update. The programme moves on with open risks and finds them again at launch.