E-Archive

Standards Forum

in Vol. 18 - May Issue - Year 2017
Matrix Analysis of Requirements
Paul Huyton

Paul Huyton

Technical standards and specifications are produced to ensure that processes, materials and components conform to the customers’ requirements and the intended use. Suppliers working in industry sectors that use technical standards must be capable of rigorously analysing the technical requirements in their customer’s specifications and those invoked by embedded specifications or implied by the supplier qualification requirements.

The customer’s requirement is primarily stated in the purchase order or standing contract, as this is the legal agreement between a customer and their supplier. The purchase order may state a specification for the material or process, or it may reference a manufacturing drawing for the component part. The drawing or its associated parts-list normally contains the technical requirements or references the relevant specifications to be used. This is relatively straightforward, but becomes increasingly complicated as specifications embedded in the primary specification may provide additional requirements.

Further to any embedded specifications, there may be supplier qualification requirements such as Nadcap approval, which can add to the requirements. Such approvals are not specifications in themselves, but an expectation of the best practice in undertaking the work.

As an example, a supplier may receive a purchase order to manufacture a part to the drawing supplied. This drawing then requires processing to AMS2432 Shot Peening, Computer Monitored. On reviewing this specification, the supplier will find that many requirements are in the embedded specification AMS 2430 Shot Peening, Automatic. This specification must therefore be reviewed, and it is found that some requirements are in embedded specifications such as SAE J442 or ASTM B214. If Nadcap approval is required to process this part, then the checklist AC7117 will also have some embedded specifications, which must be conformed to.

The complication in understanding which specifications are applicable can be clarified by use of specification matrices, which give a quick reference of relevant specifications according to the activity. Here is a simple example of this technique for activities prior to shot peening the part.

Requirement:

AMS 2432

AMS 2430

AC 7117

When applied

On PO or part dwg.

On PO or part dwg.

When Nadcap approval needed

Shot size test machine

As AMS 2430 →

ASTM B214

SAE J444

Shot size test sieves

As AMS 2430 →

ASTM E-11

ASTM E-11

Almen strips

SAE J442 + enhancements

SAE J442

SAE J442 & customer requirements

Almen gauge

SAE J442 + end stops

SAE J442

SAE J442

Saturation curve construction

As AMS 2430 →

SAE J443

SAE J443

Operator training & qualification

As AMS 2430 →

Paragraph 4.3.4

Section 7 requirements

High- and low-level matrices can be produced; high level would be a matrix with all of the prime customers e.g. Rolls-Royce, Boeing, Airbus. The matrix would indicate all of the relevant specifications for activities such as heat treatments, chemical processes, shot peening, etc. Low-level matrices can give more details of equipment and procedures for each process.

The intelligent use of these matrices will systemise the specification review and will make the review of new contracts and enquiries much more efficient. Matrices also help planning the work as they help to determine the configuration and quality control aspects of processing.

For questions contact paul@mfn.li

Standards Forum
by Paul Huyton,
MFN Course Director World Wide
more information at www.mfn.li/trainers