computer science

Sally Shlaer

Sally Shlaer is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sally Shlaer rather than just read about it. In short: Sally Shlaer (December 3, 1938 – November 12, 1998) was an American mathematician, software engineer and software methodologist, known as co-developer of the 1980s Shlaer–Mellor method for software development. Biography Born in Cleveland, Ohio, Shlaer received a BS in Mathematics in 1960 from Stanford University and started a graduate study at the Australian National University.

Key takeaways

Sally Shlaer belongs to computer science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Sally Shlaer to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Sally Shlaer from memory before moving on to harder problems.

Reference excerpt

Biography Born in Cleveland, Ohio, Shlaer received a BS in Mathematics in 1960 from Stanford University and started a graduate study at the Australian National University. At Stanford Shlaer had started programming in Fortran and assembler. In 1965 she started as a software engineer at Los Alamos National Laboratory. In 1977 she became project manager in software development at Lawrence Berkeley Laboratory, where she guided the development of a new Integrated Control System for the Bay Area Rapid Transit system. At Lawrence Berkeley, Laboratory Shlaer met Stephen J. Mellor, with whom she developed the Shlaer–Mellor method for software development. In 1985 together they founded the software development firm Project Technology Inc. Shlaer was also a Fellows of the Association for Computing Machinery.

Work

Software engineering Shlaer started her software engineering career at Los Alamos National Laboratory as a programmer. She designed and implemented an operating system to operate an electron accelerator to work in real time, and this project became her masterpiece. At Lawrence Berkeley Laboratory, she led a team of software developers to build a new control system for the subway of the Bay Area Rapid Transit system. The existing control system software was considered impossible to continue using, making replacement necessary. Working with Steve Mellor, they replaced the original Fortran and assembly language code with new code, going from seventy thousand lines to two thousand. This analysis has since been called "legendary".

Shlaer–Mellor method In the developing of a new control system for the Bay Area Rapid Transit, Shlaer and Mellor sought to regulate mechanisms of software development and began to design new methods of project management. This resulted in the development of the Shlaer–Mellor method, which in the new millennium has evolved into Executable UML.

Publications 1988. Object Oriented Systems Analysis: Modeling the World in Data. With Stephen J. Mellor. Prentice Hall, 1988. 1991. Object Life Cycles: Modeling the World In States. With Stephen J. Mellor. Prentice Hall, 1991. Articles, a selection:

1992. "A Comparison of OOA and OMT" Project Technology, Inc. White paper 1996. "The Shlaer-Mellor Method". Project Technology, Inc. White paper 1997. "Recursive Design of an Application-Independent Architecture" With Stephen J. Mellor in IEEE Software, January 1997.

References

External links

Sally Shlaer Obituary by J.L. Pimsleur, 1999 Sally Shlaer Obituary by M. Page-Jones, 1999 Sally Shlaer Up-Close and Personal Conversation on geekchic.com/replique

Illustrations

Worked examples

Example 1 — a first encounter with Sally Shlaer

Start with the simplest possible case. Write down what Sally Shlaer claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sally Shlaer before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sally Shlaer ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sally Shlaer

In research: Sally Shlaer appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Sally Shlaer in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Sally Shlaer is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1938 births, 1998 deaths, 20th-century American engineers, so understanding it makes those chapters shorter.
In everyday life: Look for Sally Shlaer outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Sally Shlaer in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Sally Shlaer means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Sally Shlaer out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sally Shlaer in simple terms?

Sally Shlaer (December 3, 1938 – November 12, 1998) was an American mathematician, software engineer and software methodologist, known as co-developer of the 1980s Shlaer–Mellor method for software development. Biography Born in Cleveland, Ohio, Shlaer received a BS in Mathematics in 1960 from Stan…

Why does Sally Shlaer matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sally Shlaer?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sally Shlaer.