Software Architecting and RUP.pdf

IBM Software Group

®

IBM Software Group

®

Software Architecting and RUP

Peter [email protected]

IBM Software Group | Rational softwareIBM Software Group | Rational software

Agenda� Introduction

�Architecture, Architect, Architecting

� Process precedents

�Rational Unified Process

�GS-Method

� RUP and Architecting

�Requirements

�Analysis and design

�Implementation

�Test

�Project management

�Configuration and change management

�Environment

� Summary


Architecture, Architect, Architecting


Architecture

� Architecture is the fundamental organization of a system embodied in

its components, their relationships to each other, and to the

environment, and the principles guiding its design and evolution.

[IEEE 1471]

� The software architecture of a program or computing system is the

structure or structures of the system, which comprise software

elements, the externally visible properties of those elements, and the

relationships among them. [Bass]

� [Architecture is] the organizational structure and associated behavior

of a system. An architecture can be recursively decomposed into

parts that interact through interfaces, relationships that connect parts,

and constraints for assembling parts. Parts that interact through

interfaces include classes, components and subsystems. [UML 1.5]


An architecture defines structure


An architecture defines behaviour


An architecture is concerned with significant elements

� The element relates to some critical functionality of the

system

�E.g. monetary transactions

� The element relates to some critical property of the system

�E.g. reliability

� The element relates to a particular architectural challenge

�E.g. external system integration

� The element is associated with a particular technical risk

� The element relates to a capability that is considered to be

unstable

� The element relates to some key element of the solution

�E.g. login mechanism


An architecture meets stakeholder needs� The end user is concerned with intuitive and correct behavior,

performance, reliability, usability, availability and security

� The system administrator is concerned with intuitive behavior,

administration and tools to aid monitoring

� The marketer is concerned with competitive features, time to market,

positioning with other products, and cost

� The customer is concerned with cost, stability and schedule

� The developer is concerned with clear requirements, and a simple and

consistent design approach

� The project manager is concerned with predictability in the tracking of the

project, schedule, productive use of resources and cost

� The maintainer is concerned with a comprehensible, consistent and

documented design approach, and the ease with which modifications can

be made


An architecture comes in many forms

Enterprise Architecture

System Architecture

Software

Architecture

Application

Architecture

Technical

Architecture

Hardware

Architecture

Organizational

Architecture


And …

� An architecture is part of a broader system

� An architecture embodies decisions based on rationale

� An architecture conforms to an architectural style

� An architecture is influenced by its environment

� An architecture influences organizational structure

� An architecture is present in every system


Architect

� The architect is a technical leader

� The architect understands the software development process

� The architect has knowledge of the business domain

� The architect has technology knowledge

� The architect has design skills

� The architect has programming skills

� The architect is a good communicator

� The architect makes decisions

� The architect is a mentor

� The architect is aware of organizational politics

� The architect is a negotiator

� The architect role may be fulfilled by a team

“The life of a software

architect is a long and

rapid succession of

suboptimal design

decisions taken partly in

the dark.” [Kruchten]


Architecting


Architecting

� Architecting is a science

� Architecting is an art

� Architecting spans many disciplines

� Architecting involves many stakeholders

� Architecting is involved in tradeoffs

� Architecting considers reusable assets

� Architecting is both top-down and bottom-up

� Architecting changes emphasis over time


The benefits of architecting

� Architecting addresses system qualities

� Architecting drives consensus

� Architecting ensures architectural integrity

� Architecting helps manage complexity

� Architecting provides a basis for reuse

� Architecting reduces maintenance costs

� Architecting supports impact analysis

� Architecting supports the planning process


Documenting a software architecture


Architecture description – Kruchten 4+1 views


Architecture description – GS-Method

� Component modeling

� Operational modeling


Architecture description – Siemens

Conceptual

View

Module

View

Execution

View

Code

View


Architecture description – RM-ODP

Enterprise

Viewpoint

Information

Viewpoint

Computational

ViewpointEngineering

Viewpoint

Technical

Viewpoint


Architecture description – Zachman framework

Data Function NetworkPerspectives

Abstractions

ScopePlanner

contextual

Enterprise ModelOwner

conceptual

System ModelDesigner

logical

People Time Motivation

Technology

Constrained ModelBuilder

physical

Detailed

RepresentationsSubcontractor

out-of-context

Functioning

Enterprise






�GS-Method


�Requirements


�Implementation

�Test



�Environment

� Summary


Process precedents

� Rational Unified Process

�A commercially-available offering (a product)

� GS-Method

�Used by IGS consultants

� Much commonality

�Deployed as web sites

�Fundamental concepts align as defined by the OMG’s Software

Process Engineering Metamodel (SPEM)

�Engagement models / configurations for different classes of system

• Custom development, packaged applications, EAI






�GS-Method


�Requirements


�Implementation

�Test



�Environment

� Summary


Top Ten Architectural Concerns

1. When is the architect first involved in a project?

2. What is the relationship of the architect to other project

roles?

3. What is the architect's role with respect to requirements?

4. What is the scope of an architecture?

5. How is an architecture described?

6. When and how does the architect come up with a first-cut

architecture?

7. How does the architect refine the architecture?

8. How and when does the architect consider reuse?

9. How does the architect enforce architecture integrity?

10.How does the architect know that the architecture is

stable?


RUP Key Concepts: Disciplines


RUP Key Concepts: Overview


RUP Key Concepts: Iterations


UML Models

� Model

�“A model is a complete description of a system from a particular

perspective” [RUP]


RUP Disciplines


Discipline: Requirements


Workflow Detail: Manage the Scope of the System


Use-Case Model


Use Cases – Prioritised

1. Create Auction

2. Place Bid

3. Close Auction

4. Browse Auction Catalog

5. Create Account

6. Sign In

7. Manage Account

8. Sign Out


Requirements: Architectural Concerns Addressed


RUP Disciplines


Discipline: Analysis and Design

AnalysisAnalysisAnalysis

DesignDesignDesign


Workflow Detail: Perform Architectural Synthesis


Workflow Detail: Define a Candidate Architecture


Architectural Analysis – Key Abstractions


Architectural Analysis – Analysis Mechanisms


Architectural Analysis – Layers


Analysis: Architectural Concerns Addressed


Workflow Detail: Refine the Architecture


Identify Design Mechanisms


Identify Design Elements


Identify Design Elements


Describe Run-Time Architecture


Describe Distribution


Design: Architectural Concerns Addressed


RUP Disciplines


Discipline: Implementation


Workflow Detail: Structure the Implementation Model


Structure the Implementation Model


Implementation: Architectural Concerns Addressed


RUP Disciplines


Discipline: Environment


Workflow Detail: Prepare Guidelines for an Iteration


Environment: Architectural Concerns Addressed


RUP Disciplines


Discipline: Test


Discipline: Deployment


Discipline: Configuration and Change Management


Discipline: Project Management


Summary

� Architectural concerns are addressed by activities from all

disciplines

� Architectural concerns are addressed throughout the project

lifecycle

�The architect’s involvement starts early in the process, during Inception

�Most of the “hard core” architecting occurs during Elaboration

�The architect’s role extends through Construction and Transition


Documents

Software Architecting and RUP.pdf