# 軟體工程 Chapter2
###### tags: `軟體工程`

## Three phase of the work associated with software engineering
- definetion phase : what?
- development phase : how?
- support phase : change associated with correction , adaptaion , enhancement , and prevention

## Framework Activites
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- communication
- planning
- modeling
- analysis of requirements
- design
- construction
- code generation
- testing
- deployment
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## Umbrella Activities
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- software project management
- formal technical reviews
- software quality assurance
- software configuration management
- document preparation and production
- reusability management
- measurement
- risk management
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## Types of process flow
1. linear flow

2. iterative flow

3. evolution flow

4. parallel flow

## Process Models
**Linear process model**
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##### Waterfall model
- 定義 :

- 問題 :
很少有project能按照sequential flow完成，客戶也很難把所有需求表達出來

- 適合的專案類型 :
well-defined and stable requirements

##### V model
- 定義 :
為瀑布式開發的變形，每⼀階段皆會進⾏測試，以確保該階段之產物符合要求。
- 適合的專案類型 :
適用於專案需求明確、結構穩定、風險較低的專案開發項目，如: 傳統桌面軟體開發、醫療器械軟體開發等等。
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**Prototyping model**
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- 定義 : 從poorly understood requirements開始，目標為理解整個系統的需求
- 問題 : 半成品，compromise while implementation
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##### Waterfall model with prototyping
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**Incremental model**
- 定義 :
combine elements of linear and parallel process flows，start with well-understood requirements，work with customers to evovle a final system.

- waterfall v.s. incremental
waterfall比較適合簡單的project，incremental適合複雜的。

- evolutionary v.s. incremental
一開始從部分完整功能開始，逐漸產生其他功能，最後形成一個完整系統
一開始從完整版的雛型開始，慢慢調整系統功能

**Spiral model**
- 定義 : software is developed in a series of evolutionary releases

- 問題 :
- uncertain number of cycles to construct product
- 需要專業評估風險的人(增加cost)
- problem will occur if a major risk is not uncovered and managed

- 適合的專案類型 : development of large-scale system

**Concurrent development model**
- 定義 : define a series of events that will trigger transition from state to state , used to represent iterative and concurrent elements of any process models
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**Specialized process model**
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##### Componenet-based development model(元件式開發模型)
- 定義 : 將一些可重複使用的元件調整後加入到新的project裡面
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##### Formal methods model
- 定義 : apply when a mathematical specification is to be developed , ambiguity , incompleteness , and inconsistency can be discovered and corrected more easily.

- 問題 : time-consuming and expensive
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##### Aspect-oriented software development(AOSD)
- Aspect : customer concerns that cut across multiple system functions , features and information
e.g.
user interface aspects
distribution aspects
persistence aspects
security aspects
transaction aspects

- 定義 : provide a process and methodological approach for defining , specifying , designing , and constructing aspects ； it usually adopts evolutionary and concurrent process model
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## Unified process
**phase** :
- inception : 了解客戶需求，開始初步規劃
- elaboration : 詳細、擴充規劃和use-case
- construction : 寫程式
- transition : 利用beta版本或是使用手冊測試
- production

## Personal software process(PSP)
- framework activites
- planning
- high-level design
- high-level design review
- development
- postmortem : 紀錄bug的發生原因，所有activities皆要留下紀錄
- PSP represents a disciplined , metrics-based(量化指標) approach to software engineering

## Team software process(TSP)
- 定義 : provide a defined process framework for managing , tracking and reporting the team's progress

- framework activities:
- launch
- high-level design
- implementation
- integration and test
- postmortem

## PSP , TSP , and CMMI

## The primary goal of software process
High quality = project timeliness , less work