ISO 8015-2011 pdf free download.Geometrical product specifications (GPS) Fundamentals Concepts, principles and rules
Specification geométrique des produits (GPS) — Principes fondamentaux — Concepts, principes et règles.
5.10.1 Operator concept
Specifications for workpiece features in GPS standards are formulated as specification operators. A specification operator is a set of prescribed operations in a prescribed order.
This concept allows for flexibility in specifications. The set of operations in a specification can be designed to emulate specific functional requirements, thus limiting or eliminating any ambiguity of the description of the function in the specification.
A complete specification operator defines the measurand for the specification in all significant details. This eliminates ambiguity of the specification.
The verification operator is the physical implementation of the specification operator. It may have exactly the same operations in the same order, in which case the method uncertainty is zero, or it may have different operations or perform the operations in a different order, in which case the method uncertainty is not zero.
The verification operator is not specified in the drawing. Rather, it is decided during verification to be sufficiently dose to the specification operator to keep the method uncertainty at an acceptable level.
5.10.2 Duality principle statement
The duality principle states that:
1) a GPS specification defines a GPS specification operator independent of any measurement procedure or measurement equipment, and;
2) the GPS specification operator is realized in a verification operator which is independent of the GPS specification itself, but is intended to mirror the GPS specification operator.
The GPS specification does not dictate which verification operators are acceptable. The acceptability of a verification operator is evaluated using the measurement uncertainty and any ambiguity of the specification.
5.11 Functional control principle
Each workpiece function is expressed by a functional operator and can be simulated by a set of specification operators, which again defines a set of measurands and the associated tolerances for these measurands.
The specification of a workpiece Is complete when all intended functions of the workpiece are described and controlled with GPS specifications. In most cases, the specification will be incomplete because some functions are described/controlled imperfectly or not at all. Hence, there may be a good or bad correlation between the function and the set of GPS specifications used.
Any lack of correlation between the functional requirements and the requirements of the GPS specifications results in ambiguity of the description of the function.ISO 8015-2011 pdf free download.