Docstoc

Chapter06-51

Document Sample
Chapter06-51 Powered By Docstoc
					              Application-Domain Analysis
                         Usage

                 Overview, Principles & Techniques

                        Part III & Chapter 6



                          L. Mathiassen, A. Munk-Madsen,
Version 5.0                   P. A. Nielsen & J. Stage     1
                      Application-Domain Analysis: Results

              indsæt ort
                      k


                           bed om k
                                   Kor ind sat

                                  ode
                                     t
                                                                                              Use cases
                                 Ven t på kod e

                                     k
                             indtastode
                                                               af slag
                                          get
                                Kod e modta


                           kode godk
                                  endt              fortry d                      udbetaling
                                                                                                                                  Interfaces
                                 Ven t på b eløb                         Beløb god ken dt



                                                                               end belø
                                                                            godk     b
                                          b
                                   v ælg belø


                                                   Beløb valgt
           end ikk belø
        godk    e     b                                                                                                                     Hoved                        quit-knap
                                                                                                            new-knap,
                                                                                                            dobbeltk lik på
                                                                                                            markeret artikel                                      new-knap,
                                                                                                                                                                  dobbeltk lik på
                                                                                                             new-knap,                                            markeret pers on
                                                                                                             dobbeltk lik på
                                                                                                             markeret ak tiv itet



                                                                                                             r
                                                                                                            A tikel                                                             Perso n

                                                                                                                                    new-knap, include-knap    ,
                                                                                                                                                          k
                                                                                                                                    dobbeltk lik på mar eret
                                                                                                                                    forfatter eller rev iewer


                                                                                                                                    new-knap, include-knap,
                                                                                                                                    dobbeltk lik på mar  keret
                                                                                                                                    artikel eller rev iewer
                                                                                                           quit-knap
                                                                                                                                                                                        quit-knap

                                                                                                                                                        new-knap,               new-knap,

             Lav plan                                Særdeles kompleks                      Opdatering                                                  inc lude-k nap,
                                                                                                                                                        dobbeltk lik på
                                                                                                                                                        markeret
                                                                                                                                                                                inc ludeknap,
                                                                                                                                                                                dobbeltk lik på
                                                                                                                                                                                markeret

             Konsekvensberegn plan                   Kompleks                               Signalering                                                 foredragsholder         f unk tion

                                                                                                                                         new-knap,
             Find kundeoplysninger                   Middel                                 Aflæsning                   Aktivitet        inc lude-k nap,
                                                                                                                                         dobbeltk lik på
                                                                                                                                                                             Sessio n
             Sæt indhold I plan                      Kompleks                               Opdatering                                   markeret
                                                                                                                                         sess ion


             Slet plan                               Simpel                                 Opdatering
             Lav reservation                         Middel                                 Opdatering                 quit-knap



             ...                                     ...                                    ...                                                             quit-knap




                                                                                                                new-knap, include-knap ,
                                                                                                                                  keret artikel
                                                                                                                dobbeltk lik på mar




                                                                    Functions

Version 5.0
                                                                                                                                                                                                    2
                      Application domain

   Application domain:
   The organization that
   administrates,
   monitors, or controls                                   System

   a problem domain
   Focus on:
        Actors (users and                    User
         other systems)
        Use cases
        Functions           Problem domain    Application domain
        Interfaces



Version 5.0
                                                                    3
                             Activities
              Problem-                Requirements
                                      for use                   Application-   Usage
               domain
                                                                  domain
              analys is
                                                                 analysis
                                                                               Functions
                                                                               Interfaces


                                Component
                     Model
                                  design

                                                     Spec ifications of
                                                     components




                             Specifications of
                                architecture



                                  Architec-
                                tural design

Version 5.0
                                                                                        4
         Overview of ‘Application-Domain Analysis’


                 To determine a system’s usage requirements.
Purpose
                 Application domain: An organization that administrates,
Concepts         monitors, or controls a problem domain.
                 Requirements: A system’s externally observable behavior.


                 Determine the application domain with use cases.
Principles
                 Collaborate with users.



                 A complete list of the system’s overall usage requirements.
Results
Version 5.0
                                                                               5
                                                    Results                             Account Owner
                                                                        Purpose: A person who owns an account. The
                                                                            account owner’s basic need is to be able to make
                                                                            payments with his plastic card.
                                           Actors                       Characteristic: The system’s users include many and
                                                                            very different account owners
     Use Cases        Account   Creditor    Administrator   Liquidity
                                                                        Examples: Account owner A is insecure in the use of a
                       owner                                Monitor         plastic card as a form of payment. A originally
Payment                 X          X                                        received his card because it was the only
                                                                            possibility…
Cash Withdrawal         X
Money Transfer          X          X                X
Account information     X                           X          X
Credit information                 X                X                                   Cash Withdrawal
Registration                                        X                   Use Case: Cash withdrawal is started by the
                                                                            account owner, when he wishes to use his
Monitoring                                          X                       credit card to withdraw cash from an ATM.
                                                                            The account owner inserts his card in an
Fault processing                                    X                       ATM, and is then requested via the screen to
                                                                            type his PIN code. The screen will either
                                                                            show a polite denial, the card will be rejected
                                                                            from the ATM and the process will be
                                                                            cancelled; or the screen will show a menu
                                                                            requesting the account owner to choose an
                                                                            amount of money by typing on the ATM’s
                                                                            keyboard. A new screen requests the
                                                                            account owner to approve the transaction. If
                                                                            the transaction is not approved the account
                                                                            owner is again requested to type an amount.
                                                                            Otherwise the use case ends by the ejection
                                                                            of the card, and the desired amount of
                                                                            money being paid.
                                                                        Objects: (to be added later)
                                                                        Functions: (to be added later)
     Version 5.0
                                                                                                                   6
                        Analyze Work Tasks
 What tasks exist in the              Work Tasks in the Administration
  application domain?                  System
 How is the division of labor?        •Establish new conference

 How are the different tasks          •Detailed planning of conference
  delimited?                           •Administration of participants
 Describe the tasks:                  •Registration of person
       Name and content               •Administration of articles
       Purpose                        •Information to the committees
       How is it assigned?            •Information to participants, authors, and
       Who performs it?               reviewers
       Relationships to other tasks
       Result



    Version 5.0
                                                                                    7
                               Find Actors
                                                    Account Owner
 Identify actors                      Purpose: A person who owns an account. The
      Determine the                     account owner’s basic need is to be able to
       distribution of roles of the      make payments with his plastic card.
                                      Characteristic: The system’s users include many
       works tasks related to            and very different account owners
       the system                     Examples: Account owner A is insecure in the
      Consider human actors             use of a plastic card as a form of payment. A
                                         originally received his card because it was
      Consider other systems            the only possibility for getting an ID card for
       as actors                         his checks. A only withdraws money from
                                         the ATM in emergency situations.
 Describe actors                      Account owner B is technologically curious and
      Make actor specification          uses the system often, optimally, and to the
                                         limit of its abilities. B has never had major
                                         problems in understanding the possibilities
                                         of the system, and B also examines the
                                         possibilities that are not obviously available.



Version 5.0
                                                                                     8
                    Find Use Cases (1)
  Describe use cases                            Cash Withdrawal
                                   Use Case: Cash withdrawal is started by the
          As statechart diagram      account owner, when he wishes to use his
                                      credit card to withdraw cash from an ATM.
          As text                    The account owner inserts his card in an
                                      ATM, and is then requested via the screen
                                      to type his PIN code. The screen will either
                                      show a polite denial, the card will be
                                      rejected from the ATM and the process
                                      will be cancelled; or the screen will show a
                                      menu requesting the account owner to
                                      choose an amount of money by typing on
                                      the ATM’s keyboard. A new screen
                                      requests the account owner to approve
                                      the transaction. If the transaction is not
                                      approved the account owner is again
                                      requested to type an amount. Otherwise
                                      the use case ends by the ejection of the
                                      card, and the desired amount of money
                                      being paid.
                                   Objects: (to be added later)
                                   Functions: (to be added later)

Version 5.0
                                                                                     9
              Find Use Cases (2)




Version 5.0
                                   10
                        The Procedural Pattern

                                           Insert card
                                                                  Card inserted
                   action 1
                                                         Prompt for code

              State 1                                             Waiting

                                                            Enter code
                    action 2
                                                                                       reject
                  …                                             Code entered

              State n
                                                   Code accepted                  cancel                  payment

                   action n+1
                                                                 Waiting                          Amount approved



                                                                                                    Approve amount
                                                             Choose amount

                                                                                  Amount chosen
                                Amount not approved




Version 5.0
                                                                                                              11
                         The Material Pattern
                                                               open document

      start

                                            Open
                                                                position cursor
                        action 1
                                          position
                        action 2           cursor
              General                                   Cursor positioned
              state                                                               insert
                             Process n                                             text
                                             position    select delete over–
                                              cursor     text          write
                            Process n+1

                                                          Text selected             change
     final                                                                        format



                                                                 save and close




Version 5.0
                                                                                           12
                   Actors and Classes

                        Application     Problem
                         domain         domain


                                      Classes &
          Static          Actors
                                      Structure


                                      Behavioral
       Dynamic          Use cases
                                       patterns

Version 5.0
                                                   13
                 Evaluate Critically (1)

   Systematic review
        Use cases should be simple and constitute a coherent whole
        The description of actors and use cases should provide
         understanding and overview
        Use cases should be described in enough detail to enable
         identification of functions and interface elements
   Experiment with prototypes
        A use case is best evaluated through planned prototype
         experiments




Version 5.0
                                                                      14
                     Evaluate Critically (2)
              Dimensions           The Mechanistic Extreme           The Romantic Extreme

                                Specialized job                Varied job
                                Polarized division of labor    No division of labor
              Work Content
                                Many procedures and rules      No procedures and rules
                                Regulated by rules             Regulated by consequences
                                Monitoring                     Self regulation
                                Stressful load                 No performance quotas
       Autonomy and Control
                                Little influence on own job    Great influence on own job
                                Low general influence          High general influence
                                No security                    Security
                                No self-realizations           Self-realization
          Social Relations
                                Little social interaction      Great social interaction
                                Alienated                      Integrated
                                No requirements to education   Large requirements to education
    Education and Development
                                Stagnation                     Development

Version 5.0
                                                                                          15
              Overview of ‘Usage’

              To determine how actors interact with a system.
Purpose
              Actor: An abstraction of users or other systems that interact
Concepts      with the target system.
              Use case: A pattern for interaction between the system and
              actors in the application domain.

              Determine the application domain with use cases.
Principles
              Evaluate use cases in collaboration with users.
              Assess social changes in the application domain.

              Descriptions of all use cases and actors.
Results
Version 5.0
                                                                         16
                       Exercise
   Define central actors
   Find a few central use cases and describe them using
   state chart diagrams
   Compile a complete actor table




Version 5.0
                                                          17

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:2
posted:2/21/2010
language:English
pages:17