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YiSu Grain

A fleeting mayfly in the world, a single grain in the boundless sea.

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Latest from YiSu Grain

68 recent articles

YiSu Grain

Jul 20, 2026 · R&D Management

Day 28 Architecture Design Review: From Quality Attribute Scenarios to an ATAM Case Study

This article links the six previous days of architecture training into a complete reasoning chain, applies it to a city‑wide emergency command platform case, and walks through stakeholder analysis, quality‑attribute scenarios, architectural decisions, 4+1 view modeling, ATAM evaluation, and scoring guidance.

4+1 viewATAMquality attribute scenarios

0 likes · 18 min read

Day 28 Architecture Design Review: From Quality Attribute Scenarios to an ATAM Case Study

YiSu Grain

Jul 20, 2026 · Fundamentals

Day 27: Architecture Evaluation—SAAM, ATAM, CBAM, Sensitivity & Trade‑off Points

Before investing heavy coding effort, the article shows how to evaluate an architecture by mapping high‑priority quality‑attribute scenarios to design decisions, using utility trees and distinguishing SAAM, ATAM, and CBAM, and then identifying sensitivity points, trade‑offs, risks and non‑risks through a concrete internet‑hospital case study.

ATAMCBAMSAAM

0 likes · 20 min read

Day 27: Architecture Evaluation—SAAM, ATAM, CBAM, Sensitivity & Trade‑off Points

YiSu Grain

Jul 19, 2026 · Fundamentals

From Requirements to Decisions: Why Architecture Design Isn’t Just Drawing Boxes

The article explains a systematic architecture design method that starts from business goals, functional requirements, quality attributes, and constraints, extracts architecture‑driving factors, applies ABSD or ADD processes, maps components and interfaces, and records decisions with clear rationale and trade‑offs, illustrated with an internet‑hospital case study.

ABSDADDarchitecture decisions

0 likes · 18 min read

From Requirements to Decisions: Why Architecture Design Isn’t Just Drawing Boxes

YiSu Grain

Jul 17, 2026 · Fundamentals

Day 25 – Five Classic Software Architecture Styles: Focus on System Organization

This article introduces the five classic software architecture styles—data‑flow, call/return, data‑centric, virtual‑machine, and independent component—explaining their core mechanisms, advantages, drawbacks, real‑world examples, and a five‑step method for selecting the appropriate style in system design and exams.

architecture stylesblackboarddata flow

0 likes · 28 min read

Day 25 – Five Classic Software Architecture Styles: Focus on System Organization

YiSu Grain

Jul 17, 2026 · Fundamentals

Day 24: Beyond Speed, Stability, and Security – Defining Quality Requirements with Six Elements

The article explains why vague quality goals like "fast, stable, secure" are insufficient for architecture design and shows how to turn them into measurable quality‑attribute scenarios using six fixed elements—stimulus source, stimulus, environment, artifact, response, and response metric—illustrated with concrete healthcare system examples.

PerformanceSecurityavailability

0 likes · 18 min read

Day 24: Beyond Speed, Stability, and Security – Defining Quality Requirements with Six Elements

YiSu Grain

Jul 16, 2026 · Fundamentals

Why One Architecture Diagram Isn’t Enough? Using the 4+1 View Model to Clarify a System

The article explains that a single diagram cannot capture all concerns of an internet‑hospital system, so architects should employ multiple viewpoints—logical, process, development, physical, and a scenario (+1) view—each tailored to different stakeholder needs and validated together.

4+1 view modelarchitecture documentationsoftware architecture

0 likes · 11 min read

Why One Architecture Diagram Isn’t Enough? Using the 4+1 View Model to Clarify a System

YiSu Grain

Jul 15, 2026 · R&D Management

Day 22: Architects Choose Trade‑offs, Not Just Draw Diagrams

The article explains how a system architect resolves conflicting stakeholder demands—such as simplicity for patients, strict security, rapid delivery, low cost, and high reliability—by translating them into documented, reviewable, implementable and evolvable architecture decisions and by continuously balancing business goals, quality attributes, technical constraints and cost.

Software Engineeringrisk managementsoftware design

0 likes · 24 min read

Day 22: Architects Choose Trade‑offs, Not Just Draw Diagrams

YiSu Grain

Jul 15, 2026 · R&D Management

From Tech Terms to Real Architecture Design: Day22‑Day42 Learning Roadmap

After completing the first 21 days of foundational topics, the second stage (Day22‑Day42) shifts focus to core architecture design, covering stakeholders, requirements, trade‑offs, evaluation methods, and a detailed daily syllabus that guides learners from theory to practical system design.

architecture evaluationlearning roadmapquality attributes

0 likes · 12 min read

From Tech Terms to Real Architecture Design: Day22‑Day42 Learning Roadmap

YiSu Grain

Jul 15, 2026 · Fundamentals

Day 21 – Link the Six Core Software‑Engineering Topics Before Advancing

Day 21 ties together six software‑engineering pillars—development models, requirements engineering, UML, design principles & patterns, testing, and CMMI—explains their interrelations, illustrates them with an e‑commerce order‑system case, teaches a memory‑palace recall method, and provides a 20‑question exam with answers.

CMMISoftware EngineeringUML

0 likes · 21 min read

Day 21 – Link the Six Core Software‑Engineering Topics Before Advancing

YiSu Grain

Jul 14, 2026 · R&D Management

Mastering CMMI: From Fire‑fighting to Continuous Improvement with a Memory Palace

This guide teaches a vivid memory‑palace method to recall CMMI’s five maturity levels—Initial, Managed, Defined, Quantitatively Managed, and Optimizing—explaining each level’s characteristics, key practices, common confusions, and how continuous improvement cycles like PDCA transform software processes from ad‑hoc heroics to data‑driven optimization.

CMMIPDCAmemory palace

0 likes · 16 min read

Mastering CMMI: From Fire‑fighting to Continuous Improvement with a Memory Palace