computer science

Problem frames approach

Problem frames approach 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 Problem frames approach rather than just read about it. In short: Problem analysis or the problem frames approach is an approach to software requirements analysis. It was developed by British software consultant Michael A.

Key takeaways

Problem frames approach 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 Problem frames approach to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Problem frames approach from memory before moving on to harder problems.

Reference excerpt

Problem analysis or the problem frames approach is an approach to software requirements analysis. It was developed by British software consultant Michael A. Jackson in the 1990s.

History The problem frames approach was first sketched by Jackson in his book Software Requirements & Specifications (1995) and in a number of articles in various journals devoted to software engineering. It has received its fullest description in his Problem Frames: Analysing and Structuring Software Development Problems (2001). A session on problem frames was part of the 9th International Workshop on Requirements Engineering: Foundation for Software Quality (REFSQ)] held in Klagenfurt/Velden, Austria in 2003. The First International Workshop on Applications and Advances in Problem Frames was held as part of ICSE’04 held in Edinburgh, Scotland. One outcome of that workshop was a 2005 special issue on problem frames in the International Journal of Information and Software Technology. The Second International Workshop on Applications and Advances in Problem Frames was held as part of ICSE 2006 in Shanghai, China. The Third International Workshop on Applications and Advances in Problem Frames (IWAAPF) was held as part of ICSE 2008 in Leipzig, Germany. In 2010, the IWAAPF workshops were replaced by the International Workshop on Applications and Advances of Problem-Orientation (IWAAPO). IWAAPO broadens the focus of the workshops to include alternative and complementary approaches to software development that share an emphasis on problem analysis. IWAAPO-2010 was held as part of ICSE 2010 in Cape Town, South Africa. Today research on the problem frames approach is being conducted at a number of universities, most notably at the Open University in the United Kingdom as part of its Relating Problem & Solution Structures research theme The ideas in the problem frames approach have been generalized into the concepts of problem-oriented development (POD) and problem-oriented engineering (POE), of which problem-oriented software engineering (POSE) is a particular sub-category. The first International Workshop on Problem-Oriented Development was held in June 2009.

Overview

Fundamental philosophy Problem analysis or the problem frames approach is an approach — a set of concepts — to be used when gathering requirements and creating specifications for computer software. Its basic philosophy is strikingly different from other software requirements methods in insisting that:

The best way to approach requirements analysis is through a process of parallel — not hierarchical — decomposition of user requirements. User requirements are about relationships in the real world—the application domain – not about the software system or even the interface with the software system.

It is more helpful ... to recognize that the solution is located in the computer and its software, and the problem is in the world outside. ... The computers can provide solutions to these problems because they are connected to the world outside.

The moral is clear: to study and analyse a problem you must focus on studying and analysing the problem world in some depth, and in your investigations you must be willing to travel some distance away from the computer. ... [In a call forwarding problem...] You need to describe what's there – people and offices and holidays and moving office and delegating responsibility – and what effects [in the problem world] you would like the system to achieve – calls to A's number must reach A, and [when B is on vacation, and C is temporarily working at D's desk] calls to B's or C's number must reach C.

None of these appear in the interface with the computer.... They are all deeper into the world than that.

The approach uses three sets of conceptual tools.

Tools for describing specific problems Concepts used for describing specific problems include: phenomena (of various kinds, including events), problem context, problem domain, solution domain (a.k.a. the machine), shared phenomena (which exist in domain interfaces), domain requirements (which exist in the problem domains) and specifications (which exist at the problem domain:machine interface). The graphical tools for describing problems are the context diagram and the problem diagram.

Tools for describing classes of problems (problem frames) The Problem Frames Approach includes concepts for describing classes of problems. A recognized class of problems is called a problem frame (roughly analogous to a design pattern). In a problem frame, domains are given general names and described in terms of their important characteristics. A domain, for example, may be classified as causal (reacts in a deterministic, predictable way to events) or biddable (can be bid, or asked, to respond to events, but cannot be expected always to react to events in any predictable, deterministic way). (A biddable domain usually consists of people.) The graphical tool for representing a problem frame is a frame diagram. A frame diagram looks generally like a problem diagram except for a few minor differences—domains have general, rather than specific, names; and rectangles representing domains are annotated to indicate the type (causal or biddable) of the domain.

A list of recognized classes of problems (problem frames) The first group of problem frames identified by Jackson included:

required behavior commanded behavior information display simple workpieces transformation Subsequently, other researchers have described or proposed additional problem frames.

Describing problems

The problem context Problem analysis considers a software application to be a kind of software machine. A software development project aims to change the problem context by creating a software machine and adding it to the problem context, where it will bring about certain desired effects. The particular portion of the problem context that is of interest in connection with a particular problem — the particular portion of the problem context that forms the context of the problem — is called the application domain. After the software development project has been finished, and the software machine has been inserted into the problem context, the problem context will contain both the application domain and the machine. At that point, the situation will look like this:

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Problem frames approach

Start with the simplest possible case. Write down what Problem frames approach 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 Problem frames approach 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 Problem frames approach 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 Problem frames approach

In research: Problem frames approach 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 Problem frames approach 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: Problem frames approach is common in secondary-school and first-year university syllabi. It links to neighbouring topics Software requirements, Systems analysis, Systems engineering, so understanding it makes those chapters shorter.
In everyday life: Look for Problem frames approach 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 Problem frames approach in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Problem frames approach 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 Problem frames approach out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Problem frames approach in simple terms?

Problem analysis or the problem frames approach is an approach to software requirements analysis. It was developed by British software consultant Michael A.

Why does Problem frames approach 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 Problem frames approach?

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 Problem frames approach.