Precision engineering is a subdiscipline of electrical engineering, software engineering, electronics engineering, mechanical engineering, and optical engineering concerned with designing machines, fixtures, and other structures that have exceptionally high tolerances, are repeatable, and are stable over time. These approaches have applications in machine tools, MEMS, NEMS, optoelectronics design, and many other fields.
One of the fundamental principles in precision engineering is that of determinism. System behavior is fully predictable even to nanometer-scale motions. To do the job efficiently and correctly to fit your need via modern machinery.
"The basic idea is that machine tools obey cause and effect relationships that are within our ability to understand and control and that there is nothing random or probabilistic about their behavior. Everything happens for a reason and the list of reasons is small enough to manage." - Jim Bryan
"By this we mean that machine tool errors obey cause-and-effect relationships, and do not vary randomly for no reason. Further, the causes are not esoteric and uncontrollable, but can be explained in terms of familiar engineering principles." - Bob Donaldson
Professors Hiromu Nakazawa and Pat McKeown provide the following list of goals for precision engineering:
- Create a highly precise movement.
- Reduce the dispersion of the product's or part's function.
- Eliminate fitting and promote assembly, especially automatic assembly.
- Reduce the initial cost.
- Reduce the running cost.
- Extend the life span.
- Enable the design safety factor to be lowered.
- Improve interchangeability of components so that corresponding parts made by other factories or firms can be used in their place.
- Improve quality control through higher machine accuracy capabilities and hence reduce scrap, rework, and conventional inspection.
- Achieve a greater wear/fatigue life of components.
- Make functions independent of one another.
- Achieve greater miniaturization and packing densities.
- Achieve further advances in technology and the underlying sciences. 
- NIST Manufacturing Engineering (2008).NIST Programs of the Manufacturing Engineering Laboratory. March 2008.
- Precision, MNB. "Precision Engineers | MNB Precision". MNB Precision. Retrieved 2017-01-30.
- Venkatesh, V. C. and Izman, Sudin, Precision Engineering, Tata McGraw-Hill Publishing Company Limited, 2007, page 6.