Optimal process plans for manufacturing and tolerance charting

Abstract

A graph theoretical approach is presented that permits the calculation of optimal process plans from datum hierarchy trees, which are elegant representations of tolerance charts. The theory is developed for a cost function that minimizes machine and datum changes. Restrictions on the sequence of machining operations arising from technical constraints or the layout of a group cell are taken into account. The process plans are optimal with respect to a specified datum hierarchy tree, manufacturing constraints and cost function. It is shown that the number of possible plans for real industrial trees is very large, and therefore this kind of optimization is beyond the ability of a human process planner. Trial runs with industrial parts indicate that optimization can be performed by a computer within a time period that is acceptable for industrial use.

Keywords

optimal process plan datum hierarchy tree tolerance chart group cell

References

Wade

O. R.

Tolerance Control in Design and Manufacturing, 1967 (Industrial Press, New York).

Wade

O. R.

Tolerance control. In Tool and Manufacturing Engineers Handbook, Vol. 1, Machining (Eds Drozda

T.J.

Wicks

), 1983, Ch. 2 (Society of Manufacturing Engineers, Dearborn, Michigan).

Marks

C. J.

Tolerance charts control production machining. Am Machinist, 1953, 97(5), 114–116.

Johnson

Index tolerance chart simplifies production. The Tool Engr, 1954, 32(2), 53–62.

Mooney

C. T.

How to adjust tolerance charts. The Tool Engr, 1955, 35(4), 75–81.

Gadzala

J. L.

Dimensional Control in Precision Manufacturing, 1959 (McGraw-Hill, New York).

Whybrew

Britton

G. A.

Tolerance Analysis in Manufacturing and Tolerance Charting, from Advanced Tolerancing Techniques (Ed. Zhang

H.-C.

), 1997, pp. 13–41 (John Wiley, New York).

Britton

G. A.

Whybrew

CATCH: Computer-Aided Tolerance Charting, from Advanced Tolerancing Techniques (Ed. Zhang

H.-C.

), 1997, pp. 461–489 (John Wiley, New York).

Irani

S. A.

Mittal

R. O.

Lehtihet

E. A.

Tolerance chart optimization. Int. J. Prod. Res., 1989, 27(9), 1531–1552.

10.

Whybrew

Britton

G. A.

Robinson

D. F.

Sermsuti-Anuwat

A graph-theoretic approach to tolerance charting. Int. J. Adv. Mf. Technol., 1990, 5, 175–183.

11.

Britton

G. A.

Whybrew

Tor

S. B.

An industrial implementation of computer-aided tolerance charting. Int. J. Adv. Mf. Technol., 1996, 12, 122–131.

12.

Nilsson

N. J.

Problem-Solving Methods in Artificial Intelligence, 1971 (McGraw-Hill, New York).

13.

Rocha

Muora

Ramos

Vale

Representing and generating operation sequences for manufacturing parts. In International Symposium on Assembly and Task Planning, 1999, pp. 332–337.

14.

Rocha

Ramos

Vale

Process planning using a genetic algorithm approach. In Proceedings of IEEE International Symposium on Assembly and Task Planning, 1999.

15.

Zhang

Y. F.

Nee

A. Y. C.

Using genetic algorithms in process planning for job shop machining. IEEE Trans. Evolutionary Computation, 1997, 1(4), 278–289.

16.

Reddy

Bhaskara S. V.

Shunmugam

M. S.

Narendran

T. T.

Operation sequencing in CAPP using genetic algorithms. Int. J. Prod. Res., 1999, 37(5), 1063–1074.