Practice Design Specification in CS Thinking

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

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Quick Recap

A document that describes what a software system should do, how it should behave, and what constraints it must satisfy, before coding begins. A good specification covers functional requirements (what the system does), non-functional requirements (performance, security, usability), and acceptance criteria (how to verify it works).

A spec is a blueprint for software — like an architect's plan before building a house. It answers 'what are we building and why?' before 'how?'

Showing a random 20 of 50 problems.

Example 1

challenge
Two stakeholders give conflicting acceptance criteria for 'fast': < 1s (sales) and < 3s for 99% (engineering). What is the disciplined resolution in the spec?

Example 2

challenge
A spec lists 200 requirements with no prioritization. What problem will this cause in execution?

Example 3

easy
What part of a spec states HOW to verify the system works correctly?

Example 4

medium
Write a brief design specification for a school library book search system. Include at least: purpose, inputs, outputs, and three functional requirements.

Example 5

easy
Classify: 'Login completes in under 1 second.' Functional or non-functional?

Example 6

medium
Order these: (1) gather requirements, (2) write design spec, (3) write code. Which comes BEFORE coding?

Example 7

medium
Order: (1) gather requirements, (2) write code, (3) write design spec, (4) test acceptance. What is the correct order?

Example 8

easy
A design spec should describe WHAT the system does. Which question does a spec answer FIRST?

Example 9

easy
Which is the BETTER requirement: (a) 'the system should be fast' or (b) 'search returns results within 1 second'?

Example 10

medium
A spec only lists features but no security, performance, or accessibility limits. What category is missing?

Example 11

hard
Rewrite 'the system must handle many users' into two measurable requirements.

Example 12

medium
A spec says 'the app should be secure.' Rewrite it as a measurable non-functional requirement (example).

Example 13

hard
A new privacy law mandates data deletion on request. Which type of requirement is this and where in the SDLC do you revisit?

Example 14

medium
Which requirement is properly testable: (a) 'easy to use' (b) 'a new user completes signup in <= 3 steps'?

Example 15

hard
Two stakeholders disagree about 'fast': sales wants < 1 s, engineering says < 3 s for 99%. Write a single resolved acceptance criterion.

Example 16

easy
Which is BETTER: (a) 'the app should be reliable', (b) 'the app must have 99.9% monthly uptime'?

Example 17

hard
Why is a spec that includes mockups but no acceptance criteria still incomplete?

Example 18

medium
Classify: 'The site must comply with WCAG 2.2 AA.' Functional or non-functional?

Example 19

easy
Whose involvement does a good spec require to avoid missing real needs?

Example 20

easy
Classify: 'Users can upload a profile photo.' Functional or non-functional?
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