010-calc/docs/business-case.md

Business Case

Metadata

Key	Value
ID	BC-001
CrossReference	SA-001

Version History

Date	Status	Author	Reviewer	Change	Commit
2026-10-04	Accepted	Jens Tirsvad Nielsen	S01	Initial version	8ccefff

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Executive Summary

Day 10 of the Udemy course "100 Days of Code: The Complete Python Pro Bootcamp" asks for a console calculator that uses functions, a dictionary of functions, user input, a loop and recursion. This project delivers it as a small, tested and documented Python 3.13+ program with no runtime dependencies.

Methodological and Standards Foundation

The SQA and QC framework in framework/ (plan first, then code), ISO/IEC 25010:2023 for quality characteristics, and the Python conventions of the coding-conventions skill.

Problem Statement

The assignment needs a finished, verifiable result with setup and run instructions, not a single untested script.

Business Opportunity

A compact reference project that shows the lecture concepts and can serve as the template for later course days.

Objectives

1. Add, subtract, multiply and divide two numbers from console input.
2. Store the operations as functions in a dictionary and call them through it.
3. Let the user continue with the previous result or start a new calculation, restarting by recursion.
4. Cover the behaviour with automated tests and document setup, run and tests in the README.

Scope

In Scope

Console program under src/, tests under tests/, pyproject.toml, Doxyfile, README, ASCII title and calculator, repository description and topics.

Out of Scope

Graphical or web interface, further operations, packaging for PyPI, runtime dependencies.

Expected Benefits

Tangible Benefits

A working, tested calculator and a reproducible setup with a local .venv.

Intangible Benefits

Practice with the plan-first process on a small project.

Strategic Alignment

Supports completing the Python Pro Bootcamp with reviewed, portfolio-quality projects.

Success Criteria

#	Criterion	Target	Measure
1	Operations and loop work	All tests pass	python -m pytest
2	Setup is reproducible	README steps work on a clean .venv	Manual run of the README
3	No runtime dependencies	Empty dependency list	pyproject.toml

Risks

Risk	Impact	Mitigation
Doxygen is not installed locally	Docs build not checked	README names it as optional
Token in .env leaks	Account compromise	.env stays git-ignored and is never read by the project

Assumptions

• Python 3.13 or newer is installed.
• The git host is reachable for issues and pull requests.

Constraints

• Python 3.13 or newer, venv, folders src/, tests/, docs/, constants in constants.py.
• No commit or push without the Product Owner's request.

Cost–Benefit Assessment

Costs	Benefits
A few hours of the Product Owner's time	A finished, documented assignment and a reusable project skeleton

Stakeholders

Stakeholder ID (SA)	Interest in this project
S01	Owns the assignment, does the work and accepts each milestone

Recommendation

Proceed — the scope is small, the cost is low and it completes the assignment.

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