Expressing the need
Functional analysis of the need: need versus solution, the 5W1H questions, the horned-beast diagram, the octopus diagram, main and constraint functions, criterion, level and flexibility, scope.
- 21 cards
- 4 topics
- Free
The outline, topic by topic
Each topic is weighted the way the exam weighs it.
- Concepts
- Questions
- Sort and link
- Understand
A few cards from the deck
Functional analysis: what is it?
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An approach that describes a product by what it must do for its users, regardless of how it will be built.
It keeps the choice of solution open: "track an order's status" leaves room for a site, an email or an SMS, whereas "an SMS" already closes the door.
A gym manager writes: "I need an iPhone app". What should you ask first?
- What problem must the app solve for its members?
- What is the maximum budget you are putting into this app?
- Do you prefer developing in Swift or with a cross-platform framework?
- How many of your members own an iPhone?
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What problem must the app solve for its members?
"An iPhone app" is a solution. Tracing back to the need (for example knowing whether a class is full) may show a site or an SMS fits as well, or better.
The … method examines a subject through six questions: Who, What, Where, When, How, Why.
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The 5W1H method examines a subject through six questions: Who, What, Where, When, How, Why.
It is a way to forget nothing at the start: an unanswered question flags a point of the need still to be clarified.
Horned-beast diagram: what is it?
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A diagram that states the need through three questions: who does the product serve, what does it act on, and to what end.
If the purpose cannot be put as a verb without naming a technology, the need is not understood yet.
Why describe the need through functions rather than technical solutions?
- Because a statement of need must contain no technical constraint at all
- Because a supplier cannot cost a solution imposed on it
- Because functions are shorter to write than solutions
- To leave the designer free to choose the best solution and to be able to test the result
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To leave the designer free to choose the best solution and to be able to test the result
Imposing a solution cuts off dialogue about the real need and ties acceptance to a means. A function describes a purpose: several solutions may satisfy it. A real technical constraint (existing systems to respect) keeps its place, as a constraint function.