25-Comp-B11 Advanced Software Design · December 2014
Question 3 of 26: Extracting Requirements from a Scenario
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Notes on this paper
98-Comp-B11 Advanced Software Design — National Exams, December 2014. 3 hours, closed book, no calculator permitted. The paper is organized into five parts, and candidates were instructed to answer any three (3) questions in Part I, any four (4) in Part II, any four (4) in Part III, any two (2) in Part IV, and any two (2) in Part V — only the first questions answered, in each part, as they appear in the answer book are marked. All questions carry equal weight, so the 15 questions actually marked (3+4+4+2+2 of 26) each count for 100/15 ≈ 6.7% of the paper. All 26 questions are answered below for completeness.
Reference texts: Sommerville, Software Engineering (10th ed., Pearson) — software processes, requirements engineering, agile methods, design principles; Pressman, Software Engineering: A Practitioner's Approach (9th ed.) — supplementary process and quality coverage; Gamma, Helm, Johnson & Vlissides (GoF), Design Patterns: Elements of Reusable Object-Oriented Software — structural/behavioural pattern catalogue (Proxy, Bridge, Strategy, Observer, Template Method, Composite, etc.); Sebesta, Concepts of Programming Languages (12th ed.) — polymorphism, dynamic binding, inheritance and language-level object semantics (also underpins the Java/C++ discussion in Part V); Brown, Malveau, McCormick & Mowbray, AntiPatterns: Refactoring Software, Architectures, and Projects in Crisis — anti-pattern catalogue (Question 18). Bertrand Meyer's Object-Oriented Software Construction is cited by name where the paper's own vocabulary (design by contract, open–closed principle) originates there; Barbara Liskov's 1987 substitutability paper is likewise cited by name for Question 11.
PART I — General Principles (answer any 3 of 5)
Question 3: Extracting Requirements from a Scenario (Part I)
The system shall generate a weekly, first-draft Allocation List assigning operatives to production lines, based on each operative's recorded skills, experience, holiday, and sick-leave data.
Functional
2
The system shall allow only users belonging to the Production Planning role to amend the automatically generated allocation.
Functional
3
The system shall produce a printed final Allocation List reflecting any Production Planning amendments made to the draft.
Functional
4
The first-draft list shall be available by 12:00 noon on Friday, and the final list by 5:00 pm the same day — a scheduling/timing constraint on the weekly batch run.
Non-functional (timing)
5
Only Production Planning staff may invoke the amend function — an access-control constraint on who may exercise requirement 2, distinct from the existence of the amend feature itself.
Non-functional (security)
6
The system shall currently support allocation of 100 operatives and be capable of expansion to at least 200 operatives without a redesign — a capacity/scalability constraint.
Non-functional (scalability)
Justification. Requirements 1–3 each describe a discrete SERVICE the system performs — generate, restrict-amend, and print — each independently testable by exercising that one function. Requirements 4–6 do not describe new services at all; they CONSTRAIN how requirements 1–3 must operate (by when, by whom, at what scale) and would be meaningless as standalone functions — "be fast" or "support 200 users" is not something a user invokes, it is a property the invoked functions must exhibit. This is exactly the FR/NFR test from Question 2 applied to a concrete scenario, and requirement 5 in particular shows the two categories can attach to the SAME feature (the amend function is functionally required to exist, but who may use it is a separate non-functional access-control constraint on that same function).
