Tutorial on JSP & JSD

I.    JSP - Jackson Structured Programming

Key Ideas:
    There is a difference between getting a program to work and getting it right.  A program may work, but may be wrong--it  may be difficult to read, may not model the problem to be solved, may be difficult to maintain.

1.     Flow charts (flow of control) vs structure diagrams (design)
        Design is about structure, about the relation of parts to the whole.
    .   A flow chart examines the dynamic representation of a program:  "What happens next?"
        In Jackson's thinking, the design of a program follows from the static structure of a program's text: "What is the relationship of parts to the whole?"

Structure Diagrams
Regular Expressions
• structure (tree) diagrams model programs and objects

 2.    Basic program design method (Jackson Structured Programming)

• system diagram
• input/output structure diagrams
• program structure diagram
• allocation of operations to program structure
• which part?  how many times?
• "read-ahead rule"

constructive method of design (not top-down, not stepwise refinement)

3.    Structure clashes, program decomposition, and inversion

• structure clashes

• inversion

4.    Optimization

•  Don't optimize!
•  If you have to, do it as the last step, after you have designed the program properly.

• boating example

II.    JSD is a system development method for developing information systems with a strong time dimension. JSD simulates events dynamically--as they occur in the real world. Systems developed using JSD are always real-time systems.

     JSD Tutorial: Student Loan System

     JSD and Hoare

Summary:
    JSD is an object-based system of development, where the behavior of objects is captured in an entity structure diagram.