SKEDSOFT

Quality Control Engineering

Basic concepts and definitions

Interchangeability (complete) is a property of independently produced parts or assembly units to provide state of operability and reliability of mechanisms and machines under conditions of fittingless assembling or at repair.

State of operability (operability) is a state of an item, at which values of all actual parameters correspond to the requirements of technical specifications or normative technical documentation.

Reliability is a property of an item to keep in time the values of all parameters in specified limits, that is, to ensure state of operability with time.

Concepts of interchangeability are fundamental ones for designing. They are also provided at manufacture and used at exploitation of items.

Parameters of interchangeability:

- Geometric (dimension, shape, relative position of surfaces and others);

- Physical and mechanical (specific gravity, hardness, strength and others);

- Chemical (chemical composition, admixtures);

- Electrical.