📚 Cambridge IGCSE Computer Science Case Study Practice | 剑桥 IGCSE 计算机科学案例分析实战演练
In the Cambridge IGCSE Computer Science course, case study analysis is a vital skill that bridges theoretical knowledge and real-world application. This article walks through a practical case study involving a small bookshop aiming to digitise its operations. You will learn how to break down a scenario, identify requirements, propose hardware and software solutions, consider networking, security, and ethical issues, and finally structure a complete written response – exactly as expected in your examinations.
在剑桥 IGCSE 计算机科学课程中，案例分析是一项将理论知识与实际应用联系起来的重要技能。本文将通过一个实际案例——一家希望实现数字化运营的小型书店——带你完整演练一遍案例分析流程。你将学会如何拆解场景、识别需求、提出硬件与软件方案、考量组网、安全与伦理问题，并最终组织出一份完整的书面答案，完全符合考试要求。
1. Understanding the Case Study Scenario | 理解案例场景
Begin by reading the scenario carefully. Our example: Green Leaves Bookshop is a small independent bookstore with one physical location. The owner wants to keep track of stock, process sales, manage customer loyalty points, and create an online ordering system. Currently, everything is recorded on paper, leading to frequent errors and lost time.
首先仔细阅读场景描述。我们的示例：绿页书店是一家只有一个实体店面小型独立书店。店主希望管理库存、处理销售、记录顾客积分，并建立一个在线订购系统。目前所有工作都靠纸质记录，经常出错且耗时。
Highlight key stakeholders: the owner, staff, customers, and possibly suppliers. Note the main goal – replacing a manual system with an efficient computerised solution. Identify constraints: a limited budget, small physical space, no existing IT infrastructure, and staff with basic digital literacy.
标出关键相关方：店主、店员、顾客，可能还有供应商。注意主要目标——用高效的计算机化方案取代手工系统。明确约束条件：预算有限、店面空间小、现无任何 IT 基础设施、员工只具备基本数字素养。
2. Identifying Problems with the Current System | 识别现行系统的问题
List the shortcomings of the manual system. For Green Leaves Bookshop, these include: time-consuming stock checks, frequent data entry errors, inability to quickly locate a book for a customer, no automated loyalty tracking, and no online presence, losing potential sales.
列出手工系统的缺陷。对绿页书店而言，包括：耗时的库存盘点、频繁的数据录入错误、无法快速帮顾客找到某本书、没有自动化的积分追踪、以及缺乏线上渠道导致潜在销售流失。
Describe the impact: customer dissatisfaction, revenue loss, and high staff workload. This justification will later support your proposed solution. Use precise terminology such as data redundancy, data inconsistency, and lack of real-time information.
描述影响：顾客不满、收入损失、员工工作量大。这些理由后续将用来支持你所提的方案。请使用精确术语，如数据冗余、数据不一致、缺少实时信息等。
3. Conducting a Requirements Analysis | 进行需求分析
Divide requirements into functional and non-functional categories. Functional: record sales, update stock levels automatically, generate loyalty points, produce daily sales reports, allow online book browsing and ordering. Non-functional: system must be easy to use, respond within two seconds, protect customer data, operate on a limited budget, and be scalable for future growth.
将需求划分为功能性需求和非功能性需求。功能性：记录销售、自动更新库存数量、累积积分、生成每日销售报表、允许在线浏览和订购图书。非功能性：系统必须易于使用、两秒内响应、保护顾客数据、在有限预算内运行，并能随着业务发展而扩展。
Use a table to summarise.
| Functional Requirement | Non-functional Requirement |
|---|---|
| Point-of-sale transaction processing | Response time < 2 seconds |
| Stock level auto-update | Data encryption for customer details |
| Online order placement | Initial hardware cost under £2000 |
| Loyalty point calculation | User-friendly interface for staff |
| 功能性需求 | 非功能性需求 |
|---|---|
| 销售点交易处理 | 响应时间 < 2 秒 |
| 库存水平自动更新 | 顾客数据加密 |
| 在线订单下单 | 初期硬件成本低于 £2000 |
| 积分计算 | 员工友好的界面 |
4. Hardware Selection and Justification | 硬件选择与理由
Propose hardware that fits the budget and functional needs. For the checkout counter: a sturdy desktop computer with a fast processor (e.g., Intel Core i3), 8 GB RAM, and a solid-state drive for quick boot and transaction processing. A barcode scanner to read book ISBNs eliminates manual typing errors. A receipt printer and a cash drawer complete the point-of-sale station.
在预算和功能需求范围内推荐硬件。收银台：一台耐用的台式电脑，配备高速处理器（如 Intel Core i3）、8 GB 内存和固态硬盘，以保证快速启动和交易处理。用条码扫描器读取书籍 ISBN 可消除手工输入错误。配一台收据打印机和一个钱箱便构成完整的销售点工作站。
For back-office tasks: a mid-range laptop for the owner to manage inventory, access reports, and update the website. A wireless router provides internet connectivity. For online operations, consider a cloud server instead of buying an expensive in-house server; monthly hosting fees are lower and include maintenance.
后台管理：一台中档笔记本电脑，供店主管理库存、查看报表和更新网站。一台无线路由器提供互联网连接。在线业务方面，考虑使用云服务器，而无需购买昂贵的本地服务器；按月付费成本更低且包含维护。
Justify each choice through cost, performance, and reliability. Mention alternative options, such as a tablet-based POS for greater mobility, and explain why your selection is more suitable.
每项选择都要从成本、性能和可靠性角度给出理由。提及替代方案，如基于平板电脑的移动 POS，并解释为何你的选择更适合。
5. Software Requirements and Selection | 软件需求与选择
The system needs an integrated software suite. Recommend off-the-shelf retail management software that includes POS, inventory control, customer relationship management (CRM), and basic accounting. Custom-developed software would be too expensive for a small shop. The software should run on a Windows or Linux platform and support barcode integration.
系统需要一套集成的软件组合。推荐现成的零售管理软件，包括 POS、库存控制、顾客关系管理（CRM）和基础会计功能。为小型店铺定制开发软件过于昂贵。软件应运行于 Windows 或 Linux 平台，并支持条码集成。
For the online store, a ready-made e-commerce platform like WooCommerce (an open-source plugin for WordPress) keeps costs low. It syncs inventory with the physical store when configured correctly, ensuring that a book sold online is subtracted from total stock. Spreadsheet software may supplement for ad hoc analysis, but is not a core tool.
线上商店方面，使用现成的电商平台如 WooCommerce（WordPress 的开源插件）可以保持低成本。正确配置后，它能与实体店库存同步，确保在线售出的书从总库存中减去。电子表格软件可用于临时数据分析，但并非核心工具。
Always consider software licenses, updating policies, and compatibility. Open-source options reduce costs but may require technical support.
始终要考虑软件许可证、更新策略和兼容性。开源选项能降低成本，但可能需要技术支持。
6. Networking and Communication | 网络与通信
The bookshop requires a local area network (LAN) to connect the checkout PC and the back-office laptop to the internet via the router. A wireless LAN (Wi-Fi) is sufficient and avoids messy cabling. Ensure the router has firewall features and supports WPA3 encryption for security.
书店需要一个局域网（LAN），将收银台电脑和后台笔记本电脑通过路由器连接到互联网。使用无线局域网（Wi‑Fi）已足够，且可避免布线凌乱。确保路由器具备防火墙功能，并支持 WPA3 加密以确保安全。
For the online store, the web server (cloud-hosted) must have high availability. The domain name should be registered, and an SSL certificate is essential to encrypt customer transactions, indicated by HTTPS. Email services can be handled by a professional provider like Gmail for business.
对于在线商店，网站服务器（云托管）必须具有高可用性。应注册域名，并配备 SSL 证书对顾客交易加密（通过 HTTPS 体现）。电子邮件服务可使用专业提供商，如企业版 Gmail。
. Use a simple diagram description in words: POS → LAN → Router → Internet → Cloud Server.
解释数据流的走向：柜台销售更新本地数据库，随后与云数据库同步以更新线上库存。用文字简要描述：POS → LAN → 路由器 → 互联网 → 云服务器。
7. Data Handling and Database Design | 数据处理与数据库设计
Design a simple relational database with tables: Books (BookID, Title, Author, ISBN, Price, StockLevel), Customers (CustomerID, Name, Email, LoyaltyPoints), Sales (SaleID, Date, CustomerID, TotalAmount), and SaleItems (SaleID, BookID, Quantity). Primary and foreign keys enforce referential integrity.
设计一个简单的关系数据库，包含以下表：Books（BookID, Title, Author, ISBN, Price, StockLevel）、Customers（CustomerID, Name, Email, LoyaltyPoints）、Sales（SaleID, Date, CustomerID, TotalAmount）以及 SaleItems（SaleID, BookID, Quantity）。主键和外键保证参照完整性。
Normalise the database to at least Third Normal Form (3NF) to minimise redundancy. For instance, storing customer details once and linking through CustomerID avoids repeating names in every sale record. Describe the purpose of SQL queries: adding new books, searching by title, updating stock after a sale, and retrieving monthly sales reports.
将数据库至少规范化到第三范式（3NF）以尽量减少冗余。例如，客户信息只存储一次并通过 CustomerID 关联，可避免在每笔销售记录中重复姓名。说明 SQL 查询的用途：添加新书、按书名搜索、销售后更新库存、生成月度销售报告。
Highlight data backup procedures: daily automated backups to the cloud and a weekly offline copy on an external hard drive stored offsite.
强调数据备份流程：每日自动备份至云端，每周将离线副本存储在场外的外置硬盘中。
8. System Development Approach | 系统开发方法
For a small-scale project, the waterfall model may be too rigid. Instead, recommend an iterative or agile approach, where a basic POS module is developed and tested first, then inventory management, and finally the online store. This allows user feedback after each phase and reduces risk.
对小型项目而言，瀑布模型可能过于僵化。建议采用迭代式或敏捷开发方法，先开发和测试基础 POS 模块，再开发库存管理，最后实现在线商店。这样每个阶段之后都能获得用户反馈，降低风险。
Explain the stages: analysis, rapid design, prototype, evaluation, and refinement. Because much of the software is off-the-shelf, 'development' focuses on configuration, customisation, and integration rather than coding from scratch. User training is an integral part of deployment.
说明各阶段：分析、快速设计、原型制作、评估和完善。由于大部分软件为现成产品，“开发”侧重于配置、定制和集成，而非从零编码。用户培训是部署过程中不可或缺的一部分。
9. Testing Strategies | 测试策略
Testing must cover all components. Unit testing: verify that the barcode scan correctly fetches book details. Integration testing: ensure the POS updates the database and that the online store reflects stock changes. System testing: simulate a full day of sales and check reports. Acceptance testing: the owner and staff use the system in a live environment to confirm it meets needs.
测试必须覆盖所有组件。单元测试：验证条码扫描是否能正确获取书籍信息。集成测试：确保 POS 更新数据库，且在线商店反映库存变化。系统测试：模拟一整天的销售并检查报表。验收测试：由店主和店员在生产环境中使用系统，确认满足需求。
Use both valid and invalid data. For example, scanning an non-existent ISBN should display an error message. Attempting to sell more copies than available should trigger a warning. Record test outcomes and fix bugs before final launch.
同时使用有效和无效数据。例如，扫描不存在的 ISBN 应显示错误信息；试图销售超出库存数量的书应触发警告。记录测试结果并在最终上线前修复缺陷。
10. Security and Ethical Considerations | 安全与伦理考量
Security measures must protect customer data and business information. Implement user authentication with strong passwords and role-based access: cashiers can only process sales, while the owner can access financial reports. Data at rest should be encrypted, and the database server housed in a secure cloud facility.
安全措施必须保护顾客数据和商业信息。实施用户身份验证，采用强密码和基于角色的访问控制：收银员只能处理销售，而店主能访问财务报告。静态数据应加密，数据库服务器应托管在安全的云设施内。
Ethical issues include obtaining customer consent before storing personal data (GDPR compliance), using loyalty points transparently, and never sharing data with third parties without permission. Display a privacy policy on the website. Discuss how the system could be misused, e.g., an employee altering stock levels, and state monitoring controls to detect anomalies.
伦理问题包括：存储个人数据前征得顾客同意（符合 GDPR 要求）、透明使用积分、未获许可绝不以第三方共享数据。在网站上展示隐私政策。讨论系统被滥用的可能，例如员工篡改库存水平，并说明用于检测异常的监控措施。
11. Implementation and Changeover | 实施与转换方式
Choose a changeover method. Pilot conversion is suitable: run both the manual and new systems in parallel for two weeks while training staff. This reduces risk, although it increases workload temporarily. Direct changeover would be too risky given the shop's dependence on sales records.
选择一种系统转换方式。试点平行转换较为合适：在培训员工的同时，让手工系统和新系统并行运行两周。这可以降低风险，尽管暂时会增加工作量。考虑到书店对销售记录的依赖，直接转换风险太高。
Document a detailed implementation plan: hardware delivery and setup, software installation and configuration, data migration from paper records (with careful validation), staff training sessions, and a go-live date. Emphasise the importance of data accuracy during the transfer of existing stock and customer information.
制定详细的实施计划：硬件交付与安装、软件安装与配置、纸质记录的数据迁移（需仔细校验）、员工培训课次以及正式上线日期。强调在迁移现有库存和顾客信息时保证数据准确的重要性。
12. Evaluation and Maintenance | 评估与维护
After the system goes live, evaluate its performance against the original requirements. Use metrics: average transaction time, stock accuracy rate, customer satisfaction surveys, and online sales growth. Identify any gaps, such as a need for a mobile app, and plan future enhancements.
系统上线后，对照原始需求评估其性能。衡量方式包括：平均交易时间、库存准确率、顾客满意度调查和在线销售增长。发现任何缺口，比如是否需要移动应用，并规划未来的功能增强。
Maintenance types: corrective (fixing bugs), adaptive (modifying to fit new tax laws), and perfective (adding a recommendation engine). Set a schedule for regular updates and back up tests. Allocate responsibilities – the software vendor handles patches, while the owner manages content.
维护类型：修正性维护（修复缺陷）、适应性维护（为适应新税法而修改）和完善性维护（增加推荐引擎）。制定定期更新和备份测试的时间表。分配职责——软件供应商负责补丁，店主管理内容。
Published by TutorHao | Computer Science Revision Series | aleveler.com
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