Chapter 13
Overview of Systems Development
Participants Initiating systems development Information systems planning Establishing objectives for systems development Systems development and the Internet Trends in systems development and enterprise resource planning
Participants Stakeholders Individu
/ organisasi yang merupakan penerima manfaat dari upaya pengembangan sistem
Systems analyst Profesional
yang mengkhususkan diri menganalisis dan merancang sistem bisnis
dalam
Users Individu yang berinteraksi dengan sistem secara teratur
Programmer Individu yang bertanggung jawab untuk memodifikasi
atau mengembangkan program untuk memenuhi kebutuhan pengguna
Managers System stakeholders Programmers
Systems analyst
Users
Technical specialists Vendors and suppliers
Systems Analyst • Seorang programmer atau konsultan yang merancang dan mengelola pengembangan aplikasi bisnis. • Biasanya, sistem analis lebih terlibat dalam masalah desain daripada di hari-hari coding.
Alasan khas untuk Memulai Pengembangan Sistem Proyek Masalah dengan sistem yang ada Keinginan untuk memanfaatkan peluang-peluang baru
Meningkatnya persaingan Keinginan untuk membuat lebih efektif menggunakan informasi Pertumbuhan organisasi Merger atau akuisisi Perubahan pasar atau lingkungan eksternal
Persepsi manfaat Potensial oleh Individu mampu melakukan perubahan
Proses Sistem pembangunan dimulai
Planning Perencanaan sistem informasi penerjemahan tujuan strategis dan
organisasi ke dalam inisiatif pengembangan sistem
Strategic plan
Analisis Kreatif Investigasi pendekatan baru untuk
masalah yang ada
Analisis Kritis
IS planning
Mempertanyakan berisi dan hati-
hati apakah unsur-unsur sistem yang terkait dalam cara yang paling efektif atau efisien
Systems development initiatives
Langkah-langkah dalam Perencanaan IS Strategic plan Mengembangkan tujuan keseluruhan
Proyek sistem sebelumnya tidak direncanakan
Identify IS projects Set prioritas & pilih proyek Analisis kebutuhan sumber daya Jadwal yang ditetapkan dan batas waktu Mengembangkan dokumen perencanaan Sistem Informasi
Menetapkan Tujuan Pembangunan Sistem Performance objectives Kualitas atau kegunaan dari output Kualitas atau kegunaan dari format output
Kecepatan di mana output yang dihasilkan
Cost objectives Biaya pengembangan Biaya yang berkaitan dengan keunikan sistem aplikasi Investasi tetap di hardware dan peralatan terkait On-akan biaya operasi dari sistem
Systems Development and the Internet Aplikasi dipindahkan ke Internet Penjualan penempatan order Akses informasi produk
Membangun situs Web statis Intranet tools
NetDynamics SilverStream Web-Logic Novera Netscape Communications
Systems Development Life Cycle Systems investigation Masalah dan peluang diidentifikasi
Systems analysis
It’s a “cycle”
sistem yang ada dan proses kerja dipelajari
Systems design Mendefinisikan bagaimana sistem informasi akan melakukan
apa yang harus dilakukan untuk memecahkan masalah
Systems implementation Komponen sistem dirakit dan sistem baru atau diubah
ditempatkan ke dalam operasi
Systems maintenance and review Memastikan sistem beroperasi dan dimodifikasi untuk
bersaing dengan perubahan bisnis
Systems investigation (Memahami masalah)
Systems Analysis (Memahami solusi) Systems design (Memilih dan merencanakan solusi terbaik) Systems implementation (Solusi tempat berlakunya)
Systems maintenance and review (Mengevaluasi hasil solusi)
Biaya untuk membuat perubaha n tertentu
Investigation
Analysis
Design
Time
Implementation Maintenance and review
Prototyping Operational prototype Mengakses file data real, mengedit input data, membuat perhitungan yang
diperlukan dan perbandingan, dan menghasilkan output riil
Non-operational prototype Sebuah model yang mencakup output dan input spesifikasi dan format
Rapid application development (RAD) Mempekerjakan alat, teknik, dan metodologi yang dirancang untuk
mempercepat pengembangan aplikasi, secara otomatis sumber generasi kode, dan memfasilitasi keterlibatan pengguna dalam kegiatan desain dan pengembangan
Joint application development (JAD) Melibatkan pertemuan kelompok di mana pengguna, stakeholder, dan IS
profesional bekerja sama untuk menganalisis sistem yang ada, solusi yang diusulkan, dan menentukan persyaratan untuk sistem baru atau diubah.
Rapid Application Development A programming system that enables programmers to quickly build working programs. In general, RAD systems provide a number of tools to help build graphical user interfaces that would normally take a large development effort. Two of the most popular RAD systems for Windows are Visual Basic and Delphi. Historically, RAD systems have tended to emphasize reducing development time, sometimes at the expense of generating efficient executable code. Nowadays, though, many RAD systems produce extremely fast code. Conversely, many traditional programming environments now come with a number of visual tools to aid development. Therefore, the line between RAD systems and other development environments has become blurred.
Prototyping: The Iterative Life Cycle Iteration 1
Iteration 2
Iteration 3 (final)
Determine requirements
Determine requirements
Determine requirements
Analyse alternatives
Analyse alternatives
Analyse alternatives
Specify design
Specify design
Specify design
Implement design
Implement design
Implement design
User review
User review
Changeover
General Model of Prototyping Systems development initiated Investigate and analyse problem sufficiently to develop workable solution Develop prototype
Put prototype into operation
Refine and modify prototype
Complete component or system
End-User Systems Development Life Cycle End-user systems development life cycle Setiap proyek pengembangan sistem di mana upaya primer dilakukan dengan kombinasi manajer bisnis dan pengguna
Factors Affecting Systems Development Success Managing change Requires the ability to recognize existing or potential
problems and deal with them before they become a serious threat to the success of a new or modified system
Use of project management tools
Schedule Milestone Deadline Critical path Program Evaluation Review Technique (PERT) Gantt chart
Selected Project Management Software Packages Software BeachBox ’98 Job Order
Vendor NetSQL Partners Management Software Inc.
OpenPlan Project Project Scheduler
Welcom Microsoft Scitor Corp.
Super Project
Computer Associates
Use of Computer-Aided Software Engineering (CASE) Tools CASE tools automate tasks required in a system
development effort and enforces adherence to the SDLC Upper CASE tools Tools that focus on activities associated with the early stages of
systems development
Lower CASE tools Tools that focus on the later implementation stage of systems
development
Integrated-CASE (I-CASE) tools Tools that provide links between upper- and lower-CASE packages,
allowing lower-CASE packages to generate program code from upper-CASE package generated designs
CASE Short for Computer Aided Software Engineering, a category of software that provides a development environment for programming teams. CASE systems offer tools to automate, manage and simplify the development process. These can include tools for: • • • • • •
Summarizing initial requirements Developing flow diagrams Scheduling development tasks Preparing documentation Controlling software versions Developing program code
Various companies offer CASE software capable of supporting some or all of these activities. While many CASE systems provide special support for object-oriented programming, the term CASE can apply to any type of software evelopment environment.
ISO 9000 An international standard used by IS departments to
ensure quality standards exist and are maintained in their products and services
Systems Investigation Identify potential problems and opportunities and consider
them in light of the goals of the company The investigation team Managers and stakeholders IS personnel
Task Undertake feasibility analysis
Establish system development goals Select system development methodology Prepare system development report
Feasibility Analysis Technical feasibility Can the hardware, software, and other system components be
acquired or developed to solve the problem?
Operational feasibility Can the project be put into action or operation?
Schedule feasibility Can the project be completed in a reasonable amount of time?
Economic feasibility Does the project make financial sense?
Net present value The preferred approach for ranking competing projects and
determining economic feasibility
The Systems Investigation Report A report that summarizes the results of the systems
investigation and the process of feasibility analysis and recommends a course of action Steering committee An advisory group consisting of senior management and
users from the IS department and other functional areas
Systems Analysis Typical table of contents from a systems investigations
report: 1. 2. 3. 4. 5. 6. 7.
Table of Contents Executive summary Review of goals and objectives System problems and opportunities Project feasibility Project costs Projects benefits Recommendations
Sources of Data Internal Sources
External Sources
• Users, stakeholders, managers
• Customers
• Organization charts
• Suppliers
• Forms and documents
• Stockholders
• Procedure manuals and policies
• Government agencies
• Financial reports
• Outside groups
• IS manuals
• Journals, etc.
• Other measures of business processes
• Consultants
• Competitors
Data Collection Structured Interview Unstructured Interview
Identify data sources
Direct Observation Questionnaires
Data collection
Statistical Sampling Follow-up & clarification
Data Analysis Data analysis Manipulating collected data so that it is usable for the development
team members participating in systems analysis
Data modeling A commonly accepted approach to modeling organizational objects
and associations that employ both text and graphics E.g, ER (entity relationship) diagrams
Activity modeling A method to describe related objects, associations, and activities
Data flow diagram A diagram that models objects, associations, and activities by
describing how data can flow between and around them
ER Example MID
Member
Name
Address
1
Date paid
Play
MID
Game of Golf
Date
Time
Score
Data Flow Diagram Schematic description of business processes Premise: for every activity there is some communication, transference, for flow that can be described as a data element DFDs show “logical” sequences (not physical processes)
Entity symbol
Member
Data-flow line
Tee time
Process symbol Assign Tee time
Reservation request
Course access
Member Member ID
Member
Score card
Handicap
Data-flow line
Data store
Available times
Schedule Group information
Check member in
Sort scores
Calculate handicap
Member tee time
Member card Date
Score card
Scores
Tee time
Application Flowchart Charts that show relationships among applications or systems
Order processing application
Inventory control application
Marketing analysis application
Invoicing application
Grid Charts A table that shows relationships among the various aspects of a systems development effort Database applications
Order processing applications
Customer database
X
Inventory control application Marketing analysis application Invoicing application
X X
Inventory database
X X X
Supplier database
Accounts receivable database
X X
Requirements Analysis An assessment used to determine user, stakeholder, and organizational needs
Goals and mission of the organization
Strategy translation
Systems requirements
Screen Layout Charts May be tailored for… Frequent users who require little descriptive information, or Infrequent users who require more descriptive information
For frequent users… ORDER ENTRY ORDER NO.
CUSTOMER NO.
SALES PERSON
REGION
COMMISSION
NET DOLLARS
XXXXX
XXXXX
XXXXX
XXX
XXX
XXXXX
ITEM NO.
QTY
UNIT
PRICE
DOLLARS
DISCOUNTS
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XX
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For infrequent users…
Which online option would you like to perform? (Please enter an ‘X’ to make a selection) _DATA ENTRY Enter transaction and report requests for later processing _RETRIEVALS Review online information from the database: bill of materials, where-used, routing, item data
The Systems Analysis Report Strength and weaknesses of existing system from a
stakeholder’s perspective User/stakeholder requirements for the new system Organizational requirements Description of what new information systems should do to solve the problem
Typical Table of Contents for a Report on an Existing System Johnson & Flores, Inc. Systems Analysis Report TABLE OF CONTENTS Background Information Problem or Need Statement Data Collection Data and Requirements Analysis Recommendations Appendixes of Documents, Tables, and Charts Glossary of Terms
End of Chapter 12
