047-amazon-price-tracker/docs/business-case.md

Business Case

Metadata

Key	Value
ID	BC-001
CrossReference
Language	en
Domain	it

Version History

Date	Status	Author	Reviewer	Change	Commit
2026-10-28	Accepted	Jens Tirsvad Nielsen	AI as stand-in for S01	Initial version Accepted after review (RC-001 Go)	f9765fd

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Executive Summary

Online prices on Amazon change often. This project builds a small Python bot that reads a product page, extracts the title and the price, and sends an e-mail through the Simple Mail Transfer Protocol (SMTP) when the price drops below a target. It is the Day 47 assignment of the Udemy course "100 Days of Code: The Complete Python Pro Bootcamp", built step by step: scrape a static practice page, send the alert, add request headers, then try the live Amazon page.

Methodological and Standards Foundation

Planning follows the SQA and QC framework mounted at framework/ (plan first, review each artifact against its quality control (QC) checklist). Quality is described with the International Organization for Standardization and International Electrotechnical Commission standard ISO/IEC 25010:2023 characteristics. Code follows the coding-conventions and clean-architecture skills.

Problem Statement

Checking a product price by hand every day costs time, and a short price drop is easy to miss. The course participant also needs a worked, runnable solution to compare with the course material.

Business Opportunity

A bot that checks the price on its own and sends an alert lets the participant buy at the right moment. As a public repository it also gives other course participants and visitors a readable example.

Objectives

1. Extract the product title and price as a float from the practice page with BeautifulSoup.
2. Send an e-mail with the title, the price and the buy link when the price is below the target.
3. Keep the SMTP address, e-mail address and password in a .env file, outside the source code.
4. Send browser-like request headers (User-Agent, Accept-Language, and the rest of the course set).
5. Try the same code on the live Amazon page and document what happens.
6. Publish the repository with description, topics, README and a wiki in English, Danish and Bahasa Malaysia, with a screenshot for each lecture step.

Scope

In Scope

• Python 3.13 or newer, venv, pyproject.toml, pytest, constants.py, Doxygen comments and Doxyfile.
• The four lecture steps, each delivered by its own branch and pull request.
• README from the framework template and a three-language wiki explaining what each step teaches.

Out of Scope

• Scheduling the bot to run daily.
• Solving Amazon CAPTCHAs (Completely Automated Public Turing tests, the robot-check pages) or evading bot detection.
• A user interface or a database.
• Importing, testing or committing the personal .env of the repository owner.

Expected Benefits

Tangible Benefits

• A runnable solution for the four lecture steps with tests.
• A documented repository (README, wiki, screenshots) that others can follow.

Intangible Benefits

• Practice with scraping, SMTP, environment variables and request headers.
• A clear example of plan-first work for course participants.

Strategic Alignment

The project supports the participant's learning goal in the 100 Days of Code course and the public portfolio of the Tirsvad-Udemy-100_days_of_code organisation.

Success Criteria

#	Criterion	Target	Measure
1	Price extracted from the practice page	99.99 as a float	Unit test with a saved copy of the page
2	Alert decision	E-mail text built only when price is below target	Unit tests for below, equal and above
3	Secrets outside the code	No credential in any tracked file	.env is ignored; search of the repository finds none
4	Test suite	All tests pass without network access	python -m pytest exits 0
5	Documentation	README, wiki in en, da, ms, one screenshot per step	Files exist and are linked
6	Repository metadata	Description and at least five topics set on the host	Read back from the host API

Risks

Risk	Impact	Mitigation
Amazon returns a robot-check page (CAPTCHA) or changes its HTML	The live step does not return a price	The live step is documented as best effort; the static page is the tested baseline
A token or password is committed	Credential leak	.env in .gitignore; tokens are read from .env only for repository set-up and never copied into the project
The practice page changes	A test breaks	Tests use a saved copy of the page
Sending real e-mail by accident	Unwanted mail	Tests mock SMTP; the sender is called only from main

Assumptions

• The Product Owner is S01 and reviews every step; S01 can be reached in chat.
• Gitea (the git host) at git.tirsystem.com hosts the repository; a Gitea token is in .env.
• The practice page https://appbrewery.github.io/instant_pot/ stays available.

Constraints

• Python 3.13 or newer; virtual environment .venv.
• Runtime dependencies are only the ones needed: requests, beautifulsoup4, python-dotenv.
• Layout src/, tests/, docs/; constants in constants.py.
• One branch and pull request per milestone.
• No GUI is involved, so no GUI test environment is needed.

Cost–Benefit Assessment

Costs	Benefits
A few hours of the participant's time; no licence or hosting cost	A working, tested, documented example and a reusable price alert

The assessment is qualitative on purpose: this is a learning project with no revenue and no budget, so a monetary return on investment (ROI) would be invented; the only cost is the participant's time, and the benefit is the learning and the reusable repository.

Stakeholders

Stakeholder ID (SA)	Interest in this project
S01	Product Owner, developer and reviewer; wants a working solution and a clean repository
S02	Readable, runnable code with the assignment's function names, and README run instructions
S03	A clear description, topics and README, and no runtime dependencies beyond the necessary

Recommendation

Proceed — the scope is small, the cost is low and every objective is testable.

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