Can programming language influence correctness? anguages affect the way we think about problems The tools we use have a profound(and devious) influence on our thinking habits, and, therefore on our thinking abilities?

Difficult Person Hostile-aggressie Bullies, cverwhelms, and intimidates cthers nd up to the hostile ade frot atoers-can t accept feedback on t rush into the worst thing that coul happen?)

opyright Nancy Leveson, Sept. 1999 Stage 1: Forming Team members begin to discover what behaviors are acceptable Usually highly unstructured environment Attempt to identify tasks, how to accomplish them Decisions on what information is needed Hesitant participation

Fairly primitive and predictive power limited Function Points Count number of inputs and output, user interactions, external interfaces files used Assess each for complexity and multiply by a weighting factor Used to predict size or cost and to assess project productivity

Reuse (Assume have source code, not a commercial product) Ariane 5. Therac-25. British AtC Expectation Significantly lower development costs and time. Amortize costs among all users or uses Assumptions

State Machine specifications Define behavior using states and transitions between states

Outline: Software Design Goals History of software design ideas Design principles Design methods Life belt or leg iron?(Budgen)

Abstract Model Specifications Build an abstract model of required software behavior using mathematically defined(perhaps using axioms )types(e. g sets, relations) Define operations by showing effects of that operation on the model Specification includes Model

Is there a problem? Why Hard? Syllabus EXamples AAS(FAA Advanced Automation System) FBI CIC IRS Modernization Program

武汉软件工程职业学院：《药物分析》课程教学资源（试卷习题）B卷答案