Understanding Systems and Information Analysts

Systems Analyst

• Systems analysts perform studies to find activities and goals, then decide on procedures to achieve those goals
• Like architects, they design and implement systems, aiming to improve client business profits through technology
• Analysts need skills in communication, computer technology, mathematics, statistics, commerce, and law, along with flexibility and intelligence

Systems Analyst Role

• Defines business problems
• Uses techniques to gather business information, identifying business strengths and weaknesses
• Analyzes details and creates plans to solve business problems
• Coordinates the solution development process
• Often referred to as planners
• Designs systems to achieve organizational profit
• Coordinates system testing according to standards
• For large systems, analysts assign tasks to supporters, such as system designers and programmer analysts

Information Analyst

• Information Analysts work with data, finding sources and determining correct data flow for processing
• They optimize storage and decide on information receivers, while also caring for input validation
• Analysts calculate the cost of information produced and analyze input costs
• They finalize what the output should produce

Systems Designer

• System Designers design new and current manual systems and determine how the system will generate information
• System Designers consult with information analysts regarding output and take responsibility for the system design, including flowcharts and algorithms

Programmer Analyst

• Programmer Analysts assess time and cost ratios related to memory resources and processing time
• Determines the best solution, considering the impact of variables on performance, tracing memory resources and processing of each process

SDLC (Software Development Life Cycle)

• SDLC is a cost-effective and time-efficient process used by development teams to design and build high-quality software

Preliminary Investigation

• Software development demand can originate internally or externally and are initiated by managers, employees, or system specialists
• Preliminary investigations consist of three parts:

Feasibility Study

• Preliminary investigations assess project feasibility to determine the system's potential benefit to the organization
• Important feasibility tests:
  • Technical feasibility: Evaluates a project's technical viability
  • Operational feasibility: Examines a project's operational viability and impact on existing processes
  • Economic feasibility: Assesses a project's financial viability and potential investment return
  • Social feasibility: Evaluates a project's potential social impact and stakeholder acceptance
  • Management feasibility: Estimates an organization's management team ability to execute a business project
  • Legal feasibility: Evaluates project compliance with laws and regulations
  • Time feasibility: Assesses a project's ability to be completed within a reasonable timeframe

Determination of System Requirements

• Knowledge about the business area under investigation is a key analysis point
• Analysts study business processes to answer study-related questions and work with different persons to gather details
• After gathering details, analysts study requirement data to identify features for the new system

Design and Development of Software

• The design of information systems details the requirements that were identified during systems analysis
• The design stage can be called logical design, while the development program software is called physical design
• Analyst begins the design process by identifying reports and outputs, usually designer sketches it to see how the system will appear when finished
• The system design describes the data to be input, calculated, or stored with individual data items and calculation procedures written in detail
• Detailed design information is passed to programmers with complete and clearly outlined software specifications
• Designers answer questions, clarify fuzzy areas, and handle programming issues

Development of Software

• Software developers install purchased software or write custom programs
• Programmers document the program, explaining how and why certain procedures are coded

System Testing

• Testing involves experimental use to ensure the software functions correctly and meets user expectations
• Special test data is inputted for processing, and the result examined
• Analysts allow limited users to use the system to identify unforeseen usage

Implementation, Evaluation, & Maintenance

• Testing is usually performed by someone other than the original programmers to ensure unbiased and reliable software
• Implementation includes personnel check out and putting new equipment into use, training users, installing new applications, and construct files
• Evaluation identifies system strengths and weaknesses with categorized processes:
  • Operational evaluation: Determines system functionality, ease of use, response time, information format suitability, overall reliability, and level of utilization
  • Organizational impact: Identifies and measures benefits like financial concerns, operational efficiency, and competitive impact
  • User manager assessment: Evaluates attitudes of senior and user managers, along with end-users
  • Development performance: Measures total development time and effort, budget and standard conformance, and assessment of development methods and tools
• Maintenance follows Computer Based Information Systems (CBIS)
• System design needs to accommodate future requests, refinements, or modifications, and changes to suit user requirements
• Well-documented logical and physical designs of a CBIS will facility its maintenance considerably

Fact-Finding Techniques: Interview

• Analysts use interviews to collect information from individuals or groups, such as current users or managers
• Interviews can be structured or unstructured:
  • Structured interviews ensure uniform question wording across respondents, shorter interviews, ease of administration and evaluation
  • Unstructured interviews offer greater flexibility in wording questions, which can uncover overlooked or important areas
  • High cost of preparation

Questionnaires and Record Review

• Questionnaires allow analysts to gather data about various system aspects from many people
• Standardized question formats provide more reliable data than other fact-finding approaches
• Analysts should modify questionnaires priniting and distribution
• Record Reviews involve examining recorded data about the system and its users
• Record inspection is performed, either as an introduction or later in the study, to compare actual operations with what the records indicate
• Includes written policy manuals, regulations, and standard operating procedures used by most organizations

Observation

• Observation allows analysts to gather firsthand information about activities being carried out
• This method is useful when there is a need to observe how documents are handled, processes are performed, and whether specified steps are followed
• Experience observers know what to look for and how to assess the significance of what they observe

Tools for Documenting Procedure and Decision

• Well designed, modular software is more likely to meet the maintenance, reliability and testing requirements
• Specific Tools for Documenting Procedure and Decision, include:
  • Structured flowcharts
  • Flow charts
  • Algorithms

Structured Flowcharts

• Structured flowcharts, or Nassi-Schneiderman charts, are graphic tools that enforce structure in modular and top-down software design
• They ensure a structure a programmer can retain when developing application software

Elements of Structured Flowcharts

• Process: Rectangular box means simple processes or steps in a program, representing value initialization, input/output operations, and calls to execute other procedures
• Decision: The decision symbol shows alternative conditions and program handling methods
• Iteration: The iteration symbol has operations until an indicated condition

Flow Charts

• Solutions of user requirements represented in flowchart form
• Diagrams of processing flow from top to bottom, indicate using arrows, and using Circles to connect flowchart pages
• Rectangles present a process, and Diamonds represent show condition.
• Parallelograms show input and output, and Ovals used to show a start to stop the process.

Algorithm

• Algorithms represent user requirements solutions (logic) in language, for easily understanding each step

Decision Tree

• Decision trees shows design paths for an action to be performed
• Has sub options except exit
• Give clarity of logical paths

Decision Tables

• Decision tables settles combination inputs with their corresponding outputs with a cause-effect designation
• The cause-effect table refers to cause-effect graphing to obtain the decision table

Importance of Decision Tables

• Allows testers to search effects of combinations to implement business rules
• Provides a regular way of starting complex business rules, that is helpful for developers as well as for testers
• Assists in the development process to do a better job
• Provides a technique used in both testing and requirements management
• Structured exercise to prepare requirements when dealing with complex business rules
• Used to model complicated logic

Advantages of Decision Tables

• Decision tables work iteratively which means the table created at the first iteration is used as input tables for the next tables
• Provides complete test case coverage: Aiding to reduces rework on writing test scenarios & test cases
• These tables guarantee consider every possible combination of condition
• Known as its completeness property

Data Analysis Tool

• Diagram of flow of data in a system its processing which converts data into valuable information is known as dataflow
• A graphical tool used to describe and analyze movement of data through a system including its processes, stores of data and delays
• DFD can be a tool basis for other components
• Transformation of data from input to output through process
• Logical DFD can be completed using 4 simple notations
• Symbols are as follow:
  • Direction of data flow, from an origin to a destination in document, letter, and telephone call, etc
  • Operations that use or produce data
  • External source or destination
  • What table / data store it represents

Rules Of Data Flow Diagram

• Arrows should not cross each other
• Squares, circles, and files must be properly named
• Circles (Processes) must have name started with verb and followed by noun
• Open ended rectangles (Tables) must have names in plurals
• Process that gets input but not gives an output it is an error ("infinite Sink")
• Joining of two data stores, two processes directly is not appropriate
• Two data store, external entities (source or destination), processes must be shown only once in the diagram
• Any Decomposed DFD must be consistent with the original DFD

Various Points on Data Flow Diagrams

• flow can occur together. in above DFD d. flow 1 & flow - 2 may occur
• DFD concentrate on data and the data moving through them, not on equipment
• Its important to determine when data comes in an application
• Data is saved for later on with DFD

Types of Data Flow Diagrams and Drawing Context

• System analyst must study current system
• The physical system is translated into a logical description that focuses on data and processes
• Emphasizes data and processes in order to focus on actual activities
• There are 2 types:
  • Physical data flow diagram: implementation dependent and shows what tasks are carried
  • Logical data flow diagram: implementation independent and data between processes
• The first steps in requirement analysis are to learn about the business process under investigation
• The data flow diagram describes accounts

Data Dictionary

• Data is information collected through sources and a Dictionary that stores it's information
• Data Dictionary contains information on all data elements or contents, data types, and text descriptions of the system
• Makes it easier for users and analysts to use data
• Provides all information about names that are used in system models
• Specifies types of data Dictionary
  • Integrated Data Dictionary
  • Stand Alone Data Dictionary
• Integrated Data Dictionary is a catalog that can be maintained by relational database
• Active Data Dictionary: Database that is updated automatically
• Passive Data Dictionary: Databases that have to be maintained or updated manually

Stand Alone Data Dictionary

• Database Administrator has access in managing database related data and doesn't require computer based data in storing
• Include:
  • Data elements
  • Tables
  • Indexing
  • Programs
  • Relationship

Notations on Data Dictionary

• Various data constructs used include:
  • Composition
  • Sequence
  • Selection
  • Repetition
  • Parentheses
  • Comment

Rules in Naming Data Dictionary Elements

• Follows a set of rules:
  • Meaningful Naming and capitalized
  • Unique naming and definitions
  • Aliases can be created to similar meanings
  • Self defining words should not be decomposed

Software Engineering

• The technology which covers a process, a set of methods - frame work, and an array of tools
• Computer software is the product that software engineers design and build by applying
• Delivers the computing potential embodied by computer hardware or network
• We use software like languages, packages, database, computer aided software development tools
• Plan, monitor and control from start to finish, as software evolves

Quality control

• Quality of software is whether it satisfies requirements with software and in execution
• The basis for this is software requirement specification
• Must test unit and perform system
• [1] Portability: Software work in different operating system
• [2] Usability: Used by all types of individuals, whether skilled or unskilled
• [3] Reusability: By using low coupling and cohesion we reuse in modules in different projects
• [4] Correctness: All requirements satisfied and validated
• [5] Maintainability: Preventing a software becoming invalid
• [6] Integrity (Security): Software have generated data and stored data for future purpose