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Week 11: Designing Decision Support System (Part 2) 第 11 周：设计决策支持系统（二）

Learning Objectives 学习目标

  • Apply DSS design principles to system architectures.
  • Map system components to the 3-Tier logical architecture.
  • Explain system reengineering strategies.

Step-by-Step Guide 分步指南

7.2 DSS Design and Reengineering

  • 3-Tier Logical Architecture:
    • Client Tier (Presentation): The browser, dashboard UI, and web portal where managers enter queries and view charts.
    • Application Tier (Logic/Models): The server hosting MBMS engines, processing algorithms, and calculating optimization formulas.
    • Data Tier (Storage): The DBMS, relational databases, and data warehouse holding raw and integrated data tables.
  • Business Process Reengineering (BPR): Redesigning organizational processes to align with the new computerized decision structures, eliminating manual bottlenecks.

Real-world Case: Spotify

  • Spotify's recommendations rely on a 3-tier architecture:
  • Client: Mobile/Web player UI displaying recommendation lists.
  • Application Server: Complex machine learning models filtering candidate songs.
  • Data Tier: Massive distributed databases storing song audio and metadata.

Reference: Spotify Recommendation Systems Architecture

Logical 3-Tier Architecture

Logical Tier Responsibilities Typical Component Technologies Interaction flow
Presentation Tier User interaction, rendering views, taking commands HTML5, JavaScript, CSS3 web client dashboards User clicks a button → sends HTTP request to App Tier
Application Tier Business rules, mathematical modeling calculations, solver invocation Java servlet, Python solver algorithms, MBMS middleware Invokes LP solver and formats results → returns JSON data
Data Tier Persistent data storage, transaction logs, metadata warehousing PostgreSQL database, enterprise warehouse, DBMS engines Executes SQL query to pull sales records → returns dataset

Decoupling for Scalability

By separating the Presentation, Application, and Data layers, a change in database structure (Data tier) does not break user interaction screens (Presentation tier), enabling loose-coupling.

7.2 DSS 架构设计与三层逻辑架构

  • 三层逻辑架构：
    • 客户端层（表示层 - Client Tier）： 浏览器、仪表板界面和 Web 门户，管理者在此输入查询并查看图表。
    • 应用层（逻辑/模型层 - Application Tier）： 托管 MBMS 引擎、运行处理算法和计算优化公式的服务器。
    • 数据层（存储层 - Data Tier）： 包含 DBMS、关系数据库和存储原始及集成数据表的数据仓库。
  • 业务流程重组 (BPR)： 重新设计组织工作流程以适应新的计算机化决策结构，消除传统的手工瓶颈。

真实企业案例：声田 (Spotify)

  • Spotify 的音乐推荐算法依赖于其经典的三层架构：
  • 表示层： 手机与网页播放器界面，显示推荐歌曲列表。
  • 应用层： 复杂的机器学习算法服务器，运行协同过滤歌曲筛选。
  • 数据层： 存放亿级歌曲音频文件与用户历史播放记录的分布式数据库。

参考链接： Spotify推荐系统技术架构

逻辑三层架构模型

逻辑架构分层 核心功能职责 典型技术栈 消息数据交互流
表示层 (Presentation) 用户交互交互、渲染视图界面、捕获用户命令 HTML5、JavaScript、CSS3 网页仪表板客户端 用户点击分析按钮 → 向应用层发送 HTTP 请求
应用层 (Application) 运行业务逻辑、执行数学模型计算、调用求解器 Java Web、Python 求解器模型算法、MBMS 中间件 调用规划求解算法，计算并将数据格式化为 JSON 传回
数据层 (Data) 持久化数据存储、事务运行日志、元数据仓库 PostgreSQL、Oracle 关系数据库、数据仓库引擎 执行 SQL 查询以拉取历史记录 → 返回结果数据集

松耦合与系统可扩展性

通过分离表示层、应用层和数据层，即使修改了数据库字段结构（数据层），也不会直接导致用户前端界面（表示层）发生崩溃，实现了系统架构的松耦合设计。

Concept Visualization 概念可视化

1. Client (Web UI)2. App Server (Models)3. Database (Data Tier)

Educational Infographic 教学信息图

Visual concept map explaining the key module topic: 解释该模块核心主题的视觉概念图：

User Solver System 1. submitParameters() 2. returnOptimalRoute()

📊 Practical Decision Support Suite (Week 11) 📊 实用决策支持套件（第 11 周）

📐 Draw.io 3-Tier DSS Architecture Blueprint

Layered architectural breakdown for enterprise decision support:

Tier 1 (Presentation): HTML5/CSS Macaron Dashboard Web UI Tier 2 (Application) : Python Flask API + Excel Solver / SciPy MBMS Engine Tier 3 (Data Layer) : PostgreSQL Data Warehouse + Power BI Embedded Data Source

Tips 提示

A 3-tier architecture decouples Client, Application Server, and Database. This prevents server crashes if too many users access the database directly.
三层架构将客户端、应用服务器和数据库进行解耦。这可以防止如果过多用户直接访问数据库时导致数据库崩溃。

Knowledge Check 知识自测

1. The user interface dashboard resides in which logical tier? 用户界面仪表板驻留在哪个逻辑层？

Show Explanation 显示解析
Correct Answer: Option 1 正确选项：选项 1

2. Which logical tier performs mathematical model logic and calculations? 哪个逻辑层执行数学模型逻辑和计算？

Show Explanation 显示解析
Correct Answer: Option 2 正确选项：选项 2

3. The database and data warehouse tables reside in which tier? 数据库和数据仓库表驻留在哪个层中？

Show Explanation 显示解析
Correct Answer: Option 3 正确选项：选项 3

Practical Exercise 实践练习

Task 1: Excel VLOOKUP statement to look up value in A1 from sheet 'Inventory' columns A to C, returning column 3. 任务 1: Excel VLOOKUP 语句：在 'Inventory' 表 A 到 C 列中查找 A1 的值，返回第 3 列。

Task 2: SQL query to add column 'Port' of type INT to table 'Servers'. 任务 2: SQL 查询：向 'Servers' 表中添加类型为 INT 的 'Port' 列。

Task 3: Write an HTML script tag to import a JavaScript file named 'dss.js'. 任务 3: 编写一个 HTML script 标签来导入名为 'dss.js' 的 JavaScript 文件。

Revision Guide 复习指南

Revision Checklist:

  • I can explain DSS modularity and loose-coupling design principles.
  • I understand the difference between Presentation, Application, and Data tiers.
  • I can map DSS subsystems into 3-tier configurations.

Key Concepts to Remember:

  • DSS Design and Reengineering:
    • 3-Tier Logical Architecture:
      • Client Tier (Present...

Matching Game 配对游戏

Match the term on the left with its definition on the right. 将左侧的术语与右侧的定义进行配对。

Client Tier
The server hosting calculation formulas and MBMS models托管计算公式和 MBMS 模型的服务器
Application Tier
The graphical dashboard rendering in the browser在浏览器中渲染的图形仪表板
Data Tier
The database servers storing transaction data tables存储交易数据表的数据库服务器
BPR
Fundamental redesign of business processes for computerization为实现计算机化对业务流程进行的根本性重新设计