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David Parnas

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Prof. David Lorge Parnas, Ph.D., P.Eng.(Ontario);
Dr.h.c.: ETH Zürich,Louvain,Lugano,TU Wien
Fellow: RSC,ACM,CAE,GI,IEEE; MRIA;

Professor Emeritus, CAS, Engineering, McMaster University,
Hamilton, Ontario Canada

Professor Emeritus, CSIS, University of Limerick
Limerick, Ireland

Physical Address:
Ottawa Ontario K1V 1V5
Canada

[email protected]

http://www.amadon.ca/Public/information.htm
Address: Ottawa, Ontario, Canada

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Wolfram Bartussek

Hochschule Darmstadt

William Griswold

Hashemite University

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Papers by David Parnas

Software engineering or methods for the multi-person construction of multi-version programs

Lecture Notes in Computer Science, 1975

This talk will describe some methods which have been used to produce a family of related software... more This talk will describe some methods which have been used to produce a family of related software products using many relatively unskilled programmers. The primary topics of the talk will be: I. An interpretation of the word "structure" with regard to software; 2. Criteria to be used in decomposing software into modules; 3. Problems and techniques with regard to software module specifications. The talk will be introductory in nature emphasizing the desired properties of well engineered software systems and providing an overview of new methods which have proven useful in achieving those properties.

2009 Ninth International Conference on Quality Software, 2009

Summary form only given: On the road to a successful software product, there are key milestones t... more Summary form only given: On the road to a successful software product, there are key milestones that you should not skip. Each of them is a chance to see if you are on the right path and to correct your direction if you are not. Each milestone is a document that records key design decisions in a way that allows them to be reviewed and analyzed. The meaning of each document must be precisely defined and there must be no ambiguity. If the document is vague and subject to many interpretations, it can lead you down a path from which recovery is difficult. This talk proposes and illustrates a set of software documents that can serve as precise (and immovable) milestones. It discusses how they can be analyzed and used to guide the project on the rest of its trip to completion. To obtain the necessary precision, and to make analysis possible, the documents are mathematical expressions but written in a way that makes them easy to read.

Programming R. Morris Techniques Editor On the Criteria To Be Used in Decomposing Systems into Modules

This paper discusses modularization as a mechanism for improving the flexibility and comprehensib... more 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 decom-positions are discussed. The unconventional decomposi-tion, 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.

Formal documentation of well-structured programs

ABSTRACT

Requirements Capture , Documentation , and Validation June , 13-18 1999

State Machines have been used to specify the case study "Light Control System". The ASM... more State Machines have been used to specify the case study "Light Control System". The ASM-approach allows one to specify system at different levels of abstraction. One can start with a high level description (u derstandable by the customer) and refine it (defining all used functions) to a deta iled version which is executable by a tool. It seems that functional programming and ASM are a good combination to achieve this goal. AsmGofer is an extension of Gofer wich allows one to define functions and ASMrules with the full power of functional programming. The system also supports building graphical user interfaces, so one can combine the (ex cutable) ASMspecification with an animation showing information abo ut the ASM-state. The tool has also been used for making Boerger/Schulte’s ASM for the Java Virtual Machine executable. Software Requirements Specification of the Light Contr ol System Egon Börger, Elvinia Riccobene, Joachim Schmid Universita' di Pisa, Pisa – Italy We p...

DAVIDLORGEPARNAS,PAULC.CLEMENTS,AND DAVIDM.WEISS

This paperdiscusses theorganization ofsoftware thatis inherently complex because ofverymanyarbitr... more This paperdiscusses theorganization ofsoftware thatis inherently complex because ofverymanyarbitrary details thatmust beprecisely right forthesoftware tobecorrect. Weshowhowthesoft- waredesign technique knownasinformation hiding, orabstraction, can besupplemented byahierarchically structured document, whichwe call amoduleguide. Theguide isintended toallow bothdesigners and maintainers toidentify easily theparts ofthesoftware thattheymust understand, without reading irrelevant details aboutother parts ofthe software. Thepaperincludes anextract fromasoftware moduleguide toillustrate ourproposals. IndexTerms-Abstract interfaces, information hiding, modular struc- ture ofsoftware, software engineering. I.INTRODUCTION MsORE thanfive years ago,anumberofpeople atthe NavalResearch Laboratory becameconcerned about whatwepreceived tobeagrowing gapbetween software en- gineering principles being advocated atmajor conferences and thepractice ofsoftware engineering atmanyindustrial and government...

Software Engineering Principles 3-14 August 1981

: This is the notebook from the updated edition of the well-received course originated by the Nav... more : This is the notebook from the updated edition of the well-received course originated by the Naval Research Laboratory and taught annually for the past six years. It is a two-week technical course for personnel managing a software project or designing software. The purpose of the course is to improve the participant's ability to evaluate software requirements, specifications, design, correctness, and maintainability. Its purpose is not to transform the participant into an expert software designer. The course concentrates on technical problems of software design. It introduces generally accepted design practices, as well as software design research that may result in practical design applications in the near future. Design for ease of maintenance is emphasized. All course material is unclassified. Topics covered include information-hiding modules (modules that isolate the effects of changes), abstract interfaces (a technique for designing the interfaces of information-hiding mod...

Abstract Types Defined as Classes of Variables 4- 4

TYPES DEFINED AS CLASSES OF VARIABLES 44D. L. Parnas , John E. Shore l, David Weiss i

Wikipedia Risks

STAR WARS; DREAM OR NIGHTMARE? Introduction In May of 1985, while teaching at the University of Victoria in British Columbia, I was asked by the Strategic Defense Initiative Organization the group within the Office of the US Secretary of Defense that is responsible

Software aspects of strategic defense systems

Software Fundamentals, May 17, 2001

A former member of the SD10 Panel on Computing in Support of Battle Management explains why he be... more A former member of the SD10 Panel on Computing in Support of Battle Management explains why he believes the "star wars" effort will not achieve its stated goals. DAVID LORGE PARNAS On 28 lune 2985, David Large Parnas, a respected computer scientist who has consulted extensively on United States defense projects, resigned from the Panel on Computing in Support of Battle Management, convened by the Strategic Defense lnitiattve Organization (SDIO). With his letter of

Designing software for ease of extension and contraction

Proceedings of the 3rd International Conference on Software Engineering, May 10, 1978

A procedure for designing abstract interfaces for device interface modules

Software Fundamentals, May 17, 2001

ABSTRACT

IEEE Transactions on Software Engineering Volume 26 Issue 9

A course on software engineering techniques

ACM SIGCSE Bulletin

Window: a formally specified graphics based text editor

On the preliminary report of C 3 S

Communications of the Acm, Apr 1, 1966

ABSTRACT

Use Of Aliases In Tabular Expressions

able suggestions and comments. I would also like to thank all the members of the Software Enginee... more able suggestions and comments. I would also like to thank all the members of the Software Engineering Research Group, especially Dennis Peters and Ruth Abraham for their patient explanation of their thesis works. Special thanks to my wife, Huizhu and my family, for their love, support and encouragement. Finally, I would like to thank the Communications and Information Technology Ontario (CITO), Natural Sciences and Engineering Research Council (NSERC) and Bell Canada for their nancial support.

Using mathematical models in the inspection of critical software

More on specification techniques for software modules

Software engineering or methods for the multi-person construction of multi-version programs

Lecture Notes in Computer Science, 1975

This talk will describe some methods which have been used to produce a family of related software... more This talk will describe some methods which have been used to produce a family of related software products using many relatively unskilled programmers. The primary topics of the talk will be: I. An interpretation of the word "structure" with regard to software; 2. Criteria to be used in decomposing software into modules; 3. Problems and techniques with regard to software module specifications. The talk will be introductory in nature emphasizing the desired properties of well engineered software systems and providing an overview of new methods which have proven useful in achieving those properties.

2009 Ninth International Conference on Quality Software, 2009

Summary form only given: On the road to a successful software product, there are key milestones t... more Summary form only given: On the road to a successful software product, there are key milestones that you should not skip. Each of them is a chance to see if you are on the right path and to correct your direction if you are not. Each milestone is a document that records key design decisions in a way that allows them to be reviewed and analyzed. The meaning of each document must be precisely defined and there must be no ambiguity. If the document is vague and subject to many interpretations, it can lead you down a path from which recovery is difficult. This talk proposes and illustrates a set of software documents that can serve as precise (and immovable) milestones. It discusses how they can be analyzed and used to guide the project on the rest of its trip to completion. To obtain the necessary precision, and to make analysis possible, the documents are mathematical expressions but written in a way that makes them easy to read.

Programming R. Morris Techniques Editor On the Criteria To Be Used in Decomposing Systems into Modules

This paper discusses modularization as a mechanism for improving the flexibility and comprehensib... more 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 decom-positions are discussed. The unconventional decomposi-tion, 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.

Formal documentation of well-structured programs

ABSTRACT

Requirements Capture , Documentation , and Validation June , 13-18 1999

State Machines have been used to specify the case study "Light Control System". The ASM... more State Machines have been used to specify the case study "Light Control System". The ASM-approach allows one to specify system at different levels of abstraction. One can start with a high level description (u derstandable by the customer) and refine it (defining all used functions) to a deta iled version which is executable by a tool. It seems that functional programming and ASM are a good combination to achieve this goal. AsmGofer is an extension of Gofer wich allows one to define functions and ASMrules with the full power of functional programming. The system also supports building graphical user interfaces, so one can combine the (ex cutable) ASMspecification with an animation showing information abo ut the ASM-state. The tool has also been used for making Boerger/Schulte’s ASM for the Java Virtual Machine executable. Software Requirements Specification of the Light Contr ol System Egon Börger, Elvinia Riccobene, Joachim Schmid Universita' di Pisa, Pisa – Italy We p...

DAVIDLORGEPARNAS,PAULC.CLEMENTS,AND DAVIDM.WEISS

This paperdiscusses theorganization ofsoftware thatis inherently complex because ofverymanyarbitr... more This paperdiscusses theorganization ofsoftware thatis inherently complex because ofverymanyarbitrary details thatmust beprecisely right forthesoftware tobecorrect. Weshowhowthesoft- waredesign technique knownasinformation hiding, orabstraction, can besupplemented byahierarchically structured document, whichwe call amoduleguide. Theguide isintended toallow bothdesigners and maintainers toidentify easily theparts ofthesoftware thattheymust understand, without reading irrelevant details aboutother parts ofthe software. Thepaperincludes anextract fromasoftware moduleguide toillustrate ourproposals. IndexTerms-Abstract interfaces, information hiding, modular struc- ture ofsoftware, software engineering. I.INTRODUCTION MsORE thanfive years ago,anumberofpeople atthe NavalResearch Laboratory becameconcerned about whatwepreceived tobeagrowing gapbetween software en- gineering principles being advocated atmajor conferences and thepractice ofsoftware engineering atmanyindustrial and government...

Software Engineering Principles 3-14 August 1981

: This is the notebook from the updated edition of the well-received course originated by the Nav... more : This is the notebook from the updated edition of the well-received course originated by the Naval Research Laboratory and taught annually for the past six years. It is a two-week technical course for personnel managing a software project or designing software. The purpose of the course is to improve the participant's ability to evaluate software requirements, specifications, design, correctness, and maintainability. Its purpose is not to transform the participant into an expert software designer. The course concentrates on technical problems of software design. It introduces generally accepted design practices, as well as software design research that may result in practical design applications in the near future. Design for ease of maintenance is emphasized. All course material is unclassified. Topics covered include information-hiding modules (modules that isolate the effects of changes), abstract interfaces (a technique for designing the interfaces of information-hiding mod...

Abstract Types Defined as Classes of Variables 4- 4

TYPES DEFINED AS CLASSES OF VARIABLES 44D. L. Parnas , John E. Shore l, David Weiss i

Wikipedia Risks

STAR WARS; DREAM OR NIGHTMARE? Introduction In May of 1985, while teaching at the University of Victoria in British Columbia, I was asked by the Strategic Defense Initiative Organization the group within the Office of the US Secretary of Defense that is responsible

Software aspects of strategic defense systems

Software Fundamentals, May 17, 2001

A former member of the SD10 Panel on Computing in Support of Battle Management explains why he be... more A former member of the SD10 Panel on Computing in Support of Battle Management explains why he believes the "star wars" effort will not achieve its stated goals. DAVID LORGE PARNAS On 28 lune 2985, David Large Parnas, a respected computer scientist who has consulted extensively on United States defense projects, resigned from the Panel on Computing in Support of Battle Management, convened by the Strategic Defense lnitiattve Organization (SDIO). With his letter of

Designing software for ease of extension and contraction

Proceedings of the 3rd International Conference on Software Engineering, May 10, 1978

A procedure for designing abstract interfaces for device interface modules

Software Fundamentals, May 17, 2001

ABSTRACT

IEEE Transactions on Software Engineering Volume 26 Issue 9

A course on software engineering techniques

ACM SIGCSE Bulletin

Window: a formally specified graphics based text editor

On the preliminary report of C 3 S

Communications of the Acm, Apr 1, 1966

ABSTRACT

Use Of Aliases In Tabular Expressions

able suggestions and comments. I would also like to thank all the members of the Software Enginee... more able suggestions and comments. I would also like to thank all the members of the Software Engineering Research Group, especially Dennis Peters and Ruth Abraham for their patient explanation of their thesis works. Special thanks to my wife, Huizhu and my family, for their love, support and encouragement. Finally, I would like to thank the Communications and Information Technology Ontario (CITO), Natural Sciences and Engineering Research Council (NSERC) and Bell Canada for their nancial support.

Using mathematical models in the inspection of critical software

More on specification techniques for software modules