On the criteria to be used in decomposing systems into modules

Communications of the ACM - Tập 15 Số 12 - Trang 1053-1058 - 1972
David Lorge Parnas1
1Carnegie-Mellon University, Pittsburgh, PA.

Tóm tắt

This paper discusses modularization as a mechanism for improving the flexibility and comprehensibility of a system while allowing the shortening of its development time. The effectiveness of a “modularization” is dependent upon the criteria used in dividing the system into modules. A system design problem is presented and both a conventional and unconventional decomposition are described. It is shown that the unconventional decompositions have distinct advantages for the goals outlined. The criteria used in arriving at the decompositions are discussed. The unconventional decomposition, if implemented with the conventional assumption that a module consists of one or more subroutines, will be less efficient in most cases. An alternative approach to implementation which does not have this effect is sketched.

Từ khóa


Tài liệu tham khảo

Gauthier , Richard , and Pont , Stephen . Designing Systems Programs, (C) , Prentice-Hall , Englewood Cliffs, N.J. , 1970 . Gauthier, Richard, and Pont, Stephen. Designing Systems Programs, (C), Prentice-Hall, Englewood Cliffs, N.J., 1970.

10.1145/362452.362489

10.1145/355602.361309

Parnas , D. L. Information distribution aspects of design methodology. Tech. Rept., Depart. Computer Science, Carnegie- Mellon U., Pittsburgh , Pa., 1971. Also presented at the IFIP Congress 1971 , Ljubljana, Yugoslavia. Parnas, D. L. Information distribution aspects of design methodology. Tech. Rept., Depart. Computer Science, Carnegie- Mellon U., Pittsburgh, Pa., 1971. Also presented at the IFIP Congress 1971, Ljubljana, Yugoslavia.

10.1145/363095.363143

Galler , B. , and Perlis , A. J . A View of Programming Languages , Addison-Wesley , Reading, Mass ., 1970 . Galler, B., and Perlis, A. J. A View of Programming Languages, Addison-Wesley, Reading, Mass., 1970.

10.1145/800155.805020

Parnas , D. L. On the criteria to be used in decomposing systems into modules. Tech. Rept ., Depart. Computer Science, Carnegie-Mellon U. , Pittsburgh, Pa ., 1971 . Parnas, D. L. On the criteria to be used in decomposing systems into modules. Tech. Rept., Depart. Computer Science, Carnegie-Mellon U., Pittsburgh, Pa., 1971.

Balzer , R. M. Dataless programming . Proc. AFIPS 1967 FJCC , Vol. 31 , AFIPS Press, Montvale, N.J. , pp. 535 - 544 . Balzer, R. M. Dataless programming. Proc. AFIPS 1967 FJCC, Vol. 31, AFIPS Press, Montvale, N.J., pp. 535-544.

Mealy , G. H. Another look at data . Proc. AFIPS 1967 FJCC , Vol. 31 , AFIPS Press, Montvale, N.J. , pp. 525 - 534 . Mealy, G. H. Another look at data. Proc. AFIPS 1967 FJCC, Vol. 31, AFIPS Press, Montvale, N.J., pp. 525-534.

10.1145/362919.362936