Introduction to Information Systems Analysis Foundations and by zzz22140

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									       Introduction to Information
            Systems Analysis
           Foundations and Building Blocks


                     INFO 503
                    Glenn Booker

INFO 503                Lecture #1           1
                Syllabus
• This class focuses on understanding the
  ways in which the concept for a product can
  be turned into requirements and a design
• Best to reach me by e-mail; phone if urgent
• Will cover most of textbook; will not cover
  object-oriented methods since that‟s a very
  different approach (see INFO 620)
• Yes, the text is quite repetitive

INFO 503            Lecture #1              2
                    Syllabus
• All course materials are on my web site
  http://users.snip.net/~gbooker/
• Be sure to read the General Course
  Information and Document Review Notes
  (http://users.snip.net/~gbooker/general.htm) and
   (http://users.snip.net/~gbooker/doc-review.doc)



INFO 503                Lecture #1                   3
 Why So Many Military Sources?
• They have vast experience with the
  development and acquisition of complex
  software and systems
• Which was paid for with tax dollars, so…
• Many of their lessons learned are
  freely available!
     – (Under References, look for SEI, INCOSE,
       and STSC.)

INFO 503                Lecture #1                4
                   My Biases
• DOD and FAA background, so I apologize
  for the TLA‟s (Three Letter Acronyms)
     – Speak up if I use one you don‟t know
• Use a Systems Engineering approach;
  information systems are a special case
• Mostly work with long-lived systems,
  so maintenance issues get extra attention

INFO 503                Lecture #1            5
  Soundstage Entertainment Club
• …is a case study which is followed
  throughout the textbook
• It will not generally be discussed in class
• FAST = “Framework for the Application of
  System Techniques,” (p. 80) is a term for
  the system analysis and design approach
  used by the text; it is a condensed version
  of a typical systems development method

INFO 503            Lecture #1                  6
           Information Systems
• Information systems are systems which use
  computer, database and/or data processing
  technology to store and analyze data
• A systems analyst supports development
  and maintenance of some system
• Development consists of several types of
  activities, including analysis and design of
  the system

INFO 503             Lecture #1                  7
Information System Applications
• Information system applications include
     – Transaction processing systems (TPS) to
       handle orders, payments, reservations,
       or other transactions
     – Management and executive information
       systems (MIS & EIS) produce reports to
       help run the business
     – Decision support systems (DSS) help make
       decisions or refine business rules

INFO 503                Lecture #1                8
              Stakeholders
• Stakeholders are the people who affect the
  development and creation of your system
• Note that a given person could fulfill many
  stakeholder roles, or they may be so far
  separated that they never meet!



INFO 503            Lecture #1                  9
              Types of Stakeholders
• General types of stakeholders include:
     –     System Owners
     –     System Users
     –     System Designers
     –     System Builders
     –     System Analysts
• Each of these may include many more
  specific roles
INFO 503                      Lecture #1   10
            System Owners
• The System Owner (a.k.a. sponsor)
  provides the money for a system to
  be developed
• They generally make the final decisions
  about the scope and future of the system
• Often technically ill informed


INFO 503            Lecture #1               11
              System Users
• The System User (a.k.a. end user) is the
  person who actually uses the product or
  system on a day-to-day basis to do their job
• Users may be internal (within your
  organization) or external (outside)
• Include support & professional staff,
  managers, customers, suppliers, and
  remote users

INFO 503             Lecture #1              12
                  System Users
• Often the User (client or customer) is the
  person who controls the detailed
  requirements for a system
• Warning: The text often assumes the
  System User knows a lot about the detailed
  data requirements - may or may not be true
     – If not, the System Designer must fill in

INFO 503                  Lecture #1              13
           System Designers
• System designers are the people who
  design the system (duh!)
• Often includes many technical specialties,
  such as database administrators, network
  designers, web architects, graphic artists,
  security experts, and experts in your
  business environment (a.k.a. Subject
  Matter Experts)
INFO 503             Lecture #1                 14
           System Builders
• System Builders are the people who create
  the system designed by the Designers
• Includes the most technically specific
  experts, such as application, systems,
  and database programmers, network
  and security administrators, and
  system integrators

INFO 503            Lecture #1                15
           System Analysts
• Main role is problem solving; to fix an
  existing system or create a new one
• Uses the system development life cycle
  to manage and control the solution
  of problems
• Helps bridge the gaps among the other
  stakeholders who affect creation of a system

INFO 503            Lecture #1               16
 System Development Life Cycle
• The System Development Life Cycle
  (SDLC) is a structured series of activities
  used to produce a system which is ready for
  operational or production use
• Development is followed by the support or
  maintenance phase, which is hopefully the
  longest phase of the system‟s life

INFO 503            Lecture #1              17
 System Development Life Cycle
• Any development life cycle generally
  includes five major activities:
     – Initiation - to establish the scope of the
       problem, and develop the strategy and
       goals for solving the problem
     – Analysis - to determine the problem‟s causes
       and effects, and determine what requirements
       are needed
                                          p. 37 (p. 10)
INFO 503                 Lecture #1   6th and (4th) edition   18
 System Development Life Cycle
     – Design - the architecture and structure which
       the solution should have to solve the problem
       the best way
     – Implementation - create the solution, using
       software tools, source code, hardware, etc.
     – Support and Improvement - find and fix
       existing problems in the operational system,
       and add new features

INFO 503                 Lecture #1                    19
            Software Life Cycle
• The system development life cycle is
  similar to the classic Waterfall software
  development life cycle
     – Life cycle phases are: concept development,
       requirements analysis, high and low level
       design, coding, testing, and implementation
• This course mostly covers requirements
  analysis, high- and low-level design
INFO 503                 Lecture #1                  20
           Sequential versus Iterative
• System development can be done in one
  pass through the life cycle (like the
  waterfall), or an iterative approach can
  be used                                  p. 41 (n/a)

• An iterative life cycle defines requirements
  and high level design, then does design and
  implement many times, adding more and
  more to the system each time
INFO 503               Lecture #1                  21
   Information Systems Architecture

• Contains three goal-oriented perspectives
     – Knowledge improve the Data which is stored
       or manipulated by the system
     – Processes improve how people use the system
     – Communications, which improve the
       Interfaces with people or other systems, and
       the effects of Geography on data distribution


INFO 503                 Lecture #1                    22
   Information Systems Architecture

• These three goals are met by the Builders
  of the system with three technologies
     – Database technologies to manage the data
     – Software technologies to implement
       the processes
     – Interface technologies to
       support communications


INFO 503                Lecture #1                23
           Information Services
• Information services may be located in a
  centralized organization used throughout a
  company, or it may be decentralized to
  support unique needs of each group within
  an organization
• Services may be outsourced - obtained from
  a third party, or obtained from consultants
  for each project which needs them
INFO 503            Lecture #1              24
           Information Services
• In extreme cases, a software solution
  provider may be used to support a massive
  software implementation (e.g. Oracle,
  SAP, PeopleSoft, etc.)
• Online services may provide business-to-
  business (B2B) or business-to-consumer
  (B2C) sales, or may provide product
  marketing (advertising)
INFO 503            Lecture #1                25
           Business Process Redesign
• Business Process Redesign (BPR) is the
  deliberate examination of business activities
  (processes) to reduce costs and make sure
  every step adds value to the product,
  whenever possible
• Tends to produce radical changes in
  an organization

INFO 503             Lecture #1               26
Continuous Process Improvement
• Focuses on making lots of small or
  incremental changes to business processes
  in order to keep improving quality,
  productivity, etc.
• Goal is to keep improving process maturity
  and product quality forever


INFO 503            Lecture #1                 27
           Process Maturity Models
• Quality standards and goals are often
  embodied in process maturity standards,
  to guide organizations‟ process
  improvement efforts
• The primary software standard is
  the Software Engineering Institute‟s
  (SEI‟s) Capability Maturity Model
  Integration (CMMI)
INFO 503            Lecture #1              28
                ISO 9000
• The ISO 9000 standards define a quality
  system which affects most aspects of
  a business
• Focused on manufacturing environment,
  but also applies to software development
• Need ISO 9000 certification for doing
  business with the European Union

INFO 503            Lecture #1               29
                     Globalization
• The Internet has brought global markets
  even closer together
• This affects system requirements such as
     –     Language translation
     –     Character sets to express those languages
     –     Currency exchange (got Euro?)
     –     Environmental aspects such as time zones
     –     Available labor markets

INFO 503                     Lecture #1                30
           Technology Influences
• Other technology trends have influenced
  information systems recently
     – Placement of seemingly everything on a web
       page (and the expectation that information
       system interfaces will be web-based)
     – Emergence of e-commerce and e-business
     – Security and privacy concerns
     – Freedom through wireless networking
INFO 503                Lecture #1                  31
 Refine Stakeholder Perspectives
• System Owners determine the scope of the
  system; including its purpose, vision, goals,
  objectives, costs, and benefits
• May be technologically illiterate
• Generally think in terms of development
  time and money (both development and
  maintenance costs), and how they are
  offset by the benefits of the system

INFO 503             Lecture #1               32
 Refine Stakeholder Perspectives
• System Users help determine its
  requirements; they only care what it does,
  not how it can do so (as a system user, do
  you care how a light switch works?)
• Help define products and processes for data
  input, validation, storage, and reporting
• Concerned about system interface and
  ease of use

INFO 503            Lecture #1              33
 Refine Stakeholder Perspectives
• System Designers determine how the
  system will meet the requirements,
  including the types of technology to be
  used, and its high and low level structure
• Tend to specialize their expertise: database,
  software engineering, system integration,
  networking, process improvement, etc.

INFO 503             Lecture #1               34
 Refine Stakeholder Perspectives
• System Builders create the system by
  writing code, testing it, and delivering the
  finished product
• This type of activity is not covered by this
  course, and includes network design,
  programming, etc.
• Changes most quickly with technology

INFO 503             Lecture #1                  35
                                         p. 64 (49)
              Building Blocks
• Now that the stakeholders have been
  defined, we look at their relationships to
  the building blocks of the system:
     – Knowledge (Data)
     – Process
     – Communications (Interface and Geography)



INFO 503               Lecture #1                     36
            Building Blocks
• The Geography aspect is downplayed in
  version 6 of the text
• Think of the Geography aspect as the
  effect of the physical scale of the system
  (e.g. time zones, internationalization) and
  networking among parts of a distributed
  system (how much data do I need to send
  from site A to site B every day?)
INFO 503             Lecture #1                 37
      Knowledge Building Blocks
• The System Owners only care about data in
  the broadest form of information
     – Owners want to know the state of business
       resources, such as money, inventory, sales,
       facilities, etc.
     – Owners express their concerns in simple
       statements about their business model, such as
       “CUSTOMERS are in SALES REGIONS”

INFO 503                 Lecture #1                     38
      Knowledge Building Blocks
• System Users want to know how to use the
  system to perform routine functions, such
  as placing an order or generating an
  inventory report
• They may know a lot about the data
  requirements in terms of relationships,
  including how a legacy system was used
  and could be improved upon
INFO 503           Lecture #1                 39
      Knowledge Building Blocks
• System Designers translate requirements
  into the files and tables which will be used
  to capture and manipulate them
• This is expressed as a database schema,
  which may be limited by the type of
  database tool used (Access, Oracle,
  DB2, etc.)

INFO 503             Lecture #1                  40
      Knowledge Building Blocks
• System Builders write the gory details
  which make it all happen – in some sort of
  language (SQL, COBOL, Ada, C+-, Visual
  Basic, etc.)
• Primitive systems had to use flat file
  technology, such as ISAM or FileMaker
  Pro, similar to using a spreadsheet

INFO 503            Lecture #1                 41
           Process Building Blocks
• System Owners are interested in
  business functions
• Most information systems are function-
  based, such as finance, personnel, sales, etc.
• Recent trends are to blend these systems
  into one really big system, like ERP
  (Enterprise Resource Planning)

INFO 503             Lecture #1                42
           Process Building Blocks
• System Users care about their business
  processes from the most practical
  perspective: when I get an order over the
  phone, I click on the Enter Invoice button
  and fill in the customer information…
• These processes are defined in policies,
  processes, and procedures, which are often
  defined by higher levels of management
INFO 503            Lecture #1                 43
           Process Building Blocks
• System Designers take the business
  processes, and show how they will be
  implemented and automated
• This results in application schema, which
  shows how the entire system will work
  via flowcharts, state diagrams, and/or
  structure charts

INFO 503            Lecture #1                44
           Process Building Blocks
• System Builders write applications which
  implement the processes
• Applications result from writing source
  code, compiling it to produce “object” files,
  and linking the object files to produce an
  executable application
• Prototyping may be used to generate a quick
  model of the desired application

INFO 503             Lecture #1              45
   Communications Building Blocks

• System Owners are concerned about large
  scale interfaces:
     – How does this system relate to other systems in
       this organization?
     – How does the customer relate to this system?
     – How does it relate to external systems?
     – What are the system‟s inputs and outputs?
     – Are there any legal or regulatory concerns?
INFO 503                 Lecture #1                  46
   Communications Building Blocks

• System Users are very concerned about the
  interface to themselves! (A.k.a. the human-
  computer interface or HCI)
• Use of a graphical user interface (GUI)
  is expected
• User interface should follow common
  standards for “look and feel”

INFO 503            Lecture #1              47
   Communications Building Blocks
• System Designers must bridge the gap
  between the user interfaces and the
  system-level interfaces
• They plan how the user will be able to
  navigate in the application
• And keep track of what‟s currently
  possible through state transition diagrams
  (e.g. typing „f‟ versus „Alt–f‟)

INFO 503             Lecture #1                48
   Communications Building Blocks

• System Builders create the user interfaces,
  possibly using a graphical development tool
  like Visual Basic or PowerBuilder
• Middleware, such as ODBC (Open
  Database Connectivity), is often used for
  system-level interfaces, such as
  communicating between database programs

INFO 503            Lecture #1              49
       Geography Building Blocks
• System Owners often think in terms of
  operating locations
     – Where is it most effective to operate this
       system? Labor rates, tax laws, and customs
       may affect the answer.
• How distributed will this system be?
• How will sites be affected by this system?

INFO 503                Lecture #1                  50
       Geography Building Blocks
• System Users tend to know a lot about
  the system requirements for their location
  or organization
• Be sure to get input from all kinds of
  System Users!
• Communication requirements may come
  from geographic considerations

INFO 503             Lecture #1                51
       Geography Building Blocks
• System Designers need to define the
  network configuration (topology) which
  will best serve this system
• Also need to consider how the processing
  work is divided geographically, and how
  the inputs and outputs will get to those
  locations (kind of like traffic flow)

INFO 503            Lecture #1               52
       Geography Building Blocks
• System Builders implement the means
  for communication across the network
• May use various protocols to express
  information from each network (TCP/IP,
  IPX, etc.)
• May need to consider how the system
  responds when part of it is not available

INFO 503            Lecture #1                53

								
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