A requirements specification for a software design support system

Most existing software design systems (SDSS) support the use of only a single design methodology. A good SDSS should support a wide variety of design methods and languages including structured design, object-oriented design, and finite state machines. It might seem that a multiparadigm SDSS would be expensive in both time and money to construct. However, it is proposed that instead an extensible SDSS that directly implements only minimal database and graphical facilities be constructed. In particular, it should not directly implement tools to faciliate language definition and analysis. It is believed that such a system could be rapidly developed and put into limited production use, with the experience gained used to refine and evolve the systems over time

SA++ : how to bring organizational aspects into teaching analysis and design

Because of the close connection between computer systems and organizations, organizational aspects should be taught in system development courses. Dataflow diagramming is a frequently taught technique that can model formal aspects of information processing. Socio-technical methods are intended to cover relations between people and technology in an organization. To avoid learning two techniques, the dataflow technique has been extended with two organizational aspects from socio-technical methods: goals and exceptions. Two versions of the extended technique have been used in a university course for systems analysis and design. Organizational issues were taught together with the technique. The students’ work has been evaluated. The technique is sufficiently easy to learn for students. The students also learnt to involve users in analysing their tasks through a wall graph session. However, many students did not learn sufficiently well to consider organizational impacts of computer systems or to design systems to fit organizational requirements. A possible way to cope is to give the students better background in knowledge of organizations

Abstraction and concretizing in information systems and problem domains : implications for system descriptions and theoretical frameworks

“Abstraction” is used both for denoting relations in the problem domain of an information system, and for denoting relations inside software and hardware of a computer. This calls for a clarification of the concept, such that frameworks of information system concepts and techniques for analysis and design can distinguish and compare different types of abstractions. Abstraction is specialized in the paper as follows: representation, classification, generalization, aggregation, and role-realization. The latter relation occurs often when modelling reality, but it is presented with erroneous direction of abstraction in the literature, and it is not supported by techniques for analysis. It is also shown that separating abstraction in analysis of problem domains from abstraction when designing information systems clarifies the direction of abstraction. Abstraction relations in a taxonomy of concepts for information systems science and the FRISCO framework are discussed, and improvements suggested. Jackson System Development, object-oriented analysis and design, and dataflow diagrams can be improved through extensions with the abstraction relations specified in this paper

Building Blocks for Control System Software

Software implementation of control laws for industrial systems seem straightforward, but is not. The computer code stemming from the control laws is mostly not more than 10 to 30% of the total. A building-block approach for embedded control system development is advocated to enable a fast and efficient software design process.\ud We have developed the CTJ library, Communicating Threads for Java¿,\ud resulting in fundamental elements for creating building blocks to implement communication using channels. Due to the simulate-ability, our building block method is suitable for a concurrent engineering design approach. Furthermore, via a stepwise refinement process, using verification by simulation, the implementation trajectory can be done efficiently

A brief comparison of real-time software design methods

This paper briefly attempts to compare several mainstream methods/methodologies that are used for the analysis and design of real time systems. These are i) CORE, ii) YSM, iii) MASCOT, iv) CODARTS, v) HOOD, vi) ROOM, vii) UML, viii) UML-RT. Methods i-iii are use a data driven approach, whilst methods iv-vii use an object-oriented approach. All these methods have their advantages and disadvantages. Thus it is difficult to decide which method is best suited to a particular real-time design situation. Some methods like YSM, MASCOT and CODARTS are more oriented towards designing event driven systems and reactive behavior. Object oriented methods like the UML have many diagrams obtained from other methods. In the first part of the paper each method is briefly presented and its main features are explained. In the second part a score based ranking is used to try to identify which method has the best overall characteristics for real time development. The final results are presented in a tabular form and using a bar chart. In addition to this it is explained how each method fits in the SDLC. Both the score of each method and how it fits in the SDLC must be considered when selecting methods. To conclude some other issues are explained, because the selection of one method does not automatically imply that there will not be any problems.peer-reviewe