TAIS

Wiki Article on Langefors

Theoretical Analysis of Information Systems¹ is a published approach to mathematical modeling of a general enterprise information system based on systems theory and algebra. Its results are basic and startling only to the degree in which something like what the book does has not become an element of common IS practice.

Table Of Contents

1. Systems Theory
   1. Basic Problems of Systems Theory
      1. Needs for a Formal Systems Theory
      2. Common Faults in Systems Design Analysis
      3. Different Kinds of Systems Study
      4. Systems Engineering
      5. Structural Systems Theory, Electric Networks and Elastic Systems
      6. Mathematical Systems Theory as a System
      7. Other Kinds of System Study
      8. Elements of a Systems Theory
      9. Usefulness of our Concise Definition of Systems
      10. The Systems Analysis Approach
      11. The Fundamental Principle of Systems Work
      12. General and Special Properties of System Problems
      13. Systems, Subsystems, Parts, and Boundaries
      14. Structure Types of a System
      15. System Partitioning
      16. Systems Partitioning of Outer Boundary
      17. A Sketch of a Basic Theory of Systems Analysis
      18. The Suitable Number of Subsystems in a System
   2. Systems Algebra
2. Information Systems Theory
   1. Information Systems
   2. The Function of an Information System
   3. The Economic Quantity of Information and Processing
   4. Some Problems of Information Systems Design
   5. Precedence Relations between Information Sets in and Information System
   6. Data and Information Files
   7. Files, Computations, and Processes
   8. Effect of a Process Grouping
   9. File Consolidation
   10. System Design Computation Using Matrix Algebra
   11. File Storage Considerations
   12. File Organizations
   13. System Reliability
3. Some Data Processing Problems
   1. Relation between a Process and its Files
   2. Influence of Word Structure

The approach was developed over some time before the mid-1970s and so reflects a relatively low-level focus that seems quaint in a modern context. However the material culminating in the chapter on System Design Computation is of enduring value. I believe Langefors died a few years before the turn of the century and there was both a final work by him, related work by colleagues in Regnecentralen and other organizations, and related work from unrelated sources.

Import

TAIS is significant for several reasons. One is historical. The work was published shortly after the introduction of the concept of Software Engineering and before the emergence of OOP, Design Patterns, and other currents which came to represent the mainstream of of systems analysis and design practice.

Further Reading

¹ Lagefors, B. Fourth Edition, AUERBACH. 1973 ISBN 0-87769-151-7