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Object-OrientedAnalysis & Design (OAD)

OAD Introduction

Alexander FelfernigInstitute for Software Technology

Inffeldgasse 16b/2

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Goals

Introduction to OAD Start: 16.15h (16.00h c.t.)

Course exams: altogether >= 50% (butalso the individual exams >= 50%)

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Software Systems model part of the real world

are often large and complex must be maintainable

must be highly reliable

must be user-friendly must be efficient

to build high-quality systems we need

a process with clearly defined activities (e.g., Unified Process)

techniques for supporting the activities (e.g., UML)

tools for generating the products (e.g., Visual Paradigm)

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Successful Software

Development means understanding the

requirements

prioritizing therequirements

tracing the changes knowing the risks

assuring the qualityof artifacts

-4-Approximately 40% of the total project budget is related to rework

costs triggered by low-quality requirement definitions![1]

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Software Process goal: producing high-quality products

in a disciplined process

described by a set of activities thattransform requirements into software

requirements state

services to be provided: functional requirements

non-functional requirements (e.g., response times,usability, etc.)

challenge: requirements are incomplete, notunderstandable, unstructured, inconsistent

first activity: OOA (Object Oriented Analysis)

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Why OOA? understanding of

what we want todevelop

what? vs. how?(analysis vs. design)

scenario vs.integratedstate model

object model vs.relational algebra

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Requirements Engineering main activity in OOA

requirements document: relevantrequirements for the software system

requirements capture: abstraction

classification: clustering & prioritization validation/verification: right requirements? / requirements right?

feasibility: resources available?

late error discovery triggers high costs!

next phase: OOD (Object Oriented Design)

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Why OOD? understanding of

how we willdevelopthe software

integrated statemodel vs.implementation

OCL constraintsvs. implementation

relational algebravs. database

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Design logical design

partitioning of requirements tocomponents

how do components interact?

detailed design

each component is designed individually

how does a component solve its tasks?

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Effective Teams

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For details see[3]

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Roles in Team Analysts (A): eliciting and investigating

requirements (relationship with customer)

Developers (D): designing and implementingsoftware

Managers (M): managing and configuring the

software engineering process

Testers (T): testing the software

General (G): further activities if needed

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Enterprise Applications support typical problem solving scenarios in

enterprises (e.g., online selling applications) in contrast to technical & scientific applications

in contrast to the system programming level (operatingsystems, hardware, computer networks, etc.)

are data-intensive high data volumes (e.g., millions of customers and items)

not (!) computational intensive (in contrast to technical &scientific applications )

are Input/Output (I/O)-intensive major role of data/information collection and retrieval

no complex underlying algorithms

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Enterprise Applications are transaction oriented

information/data used in a distributed environment (e.g.,

www.amazon.com) for instance, essential for functionalities related to booking,

payment, etc.

are end user oriented

applicable for users with different educational background(usability aspects, etc.)

optimal support for working processes crucial (e.g.,recommendations)

flexibility/adaptability important (e.g., sales and marketingrules regarding the recommended items have to becontinuously adapted)

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Types of E-Applications operative

day-to-day business, e.g., bookkeeping, ordermanagement, material management, recommendation, etc.

administration, lower-level management

tactic

key metrics, statistics, e.g., # of new customers per period,monthly turnover, etc.

upper-level management

strategic

planning, decision support, e.g., market forecasting

high-level management

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References1. D. Leffingwell. Calculating the return on investment

from more effective requirements management.American Programmer, 10(4):1316, 1997.

2. D. Yang, D. Wu, S. Koolmanojwong, A. Brown, and B.Boehm. WikiWinWin: A Wiki Based System for

Collaborative Requirements Negotiation, HICCS, p. 24,2008.

3. E. Demirrs, G. Sarmasik, and O. Demirrs. The Role

of Teamwork in Software Development: Microsoft CaseStudy, 23rd EUROMICRO Conference New Frontiersof Information Technology, IEEE, pp. 129-133, 1997.

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