Systems Analysis Fundamentals

• Systems Analysis and Design: Requirements Modeling
• The systems analysis phase involves:
  • Understanding the proposed project
  • Ensuring support for business requirements
  • Building a solid foundation for system development

Systems Analysis Activities

• Systems analysis involves requirements modeling, utilizing fact-finding to describe the current systems, and identifying requirements for new systems.
• It also involves data and process modeling, which graphically represents system data and processes. Object modeling creates objects to represent people, things, transactions, and events.
• Development strategies incorporate software trends, development alternatives, and outsourcing
• The systems analysis phase is interactive, even when the waterfall model depicts sequential development.
• Strong analytical and interpersonal skills are needed for systems analysis.

Team-Based Techniques: JAD, RAD, Agile Methods

• The goal is to deliver the best possible system at the lowest cost in the shortest time. Joint application Development brings users into the design process.
• Rapid application development (RAD) is a condensed version of the system development life cycle.
• Agile methods emphasize intense interaction between developers and users.

Joint Application Development (JAD)

• A fact-finding technique that brings users into the development process as active participants.
• User involvement, whether formal or informal, helps create a successful system.
• Participants include a project leader with one or more members and should be insulated from distractions.

JAD Participants and Roles

• JAD Project Leader: Develops agenda, acts as facilitator, and leads JAD sessions.

• Top Management: Provides enterprise-level authorization and project support.

• Managers: Provide project support and understanding of how the project supports business functions and requirements.

• Users: Provide operational input on current operations, desired changes, input and output needs, user interface issues, and day-to-day task support.

• Systems Analysts & IT Staff: Offer technical aid and resources on security, backup, hardware, software, and network to JAD team.

• Recorder: Captures JAD session results and collaborates with analysts to build system models and CASE tool documentation.

• A typical JAD session agenda includes introductions, ground rules discussion, explanation of documentation methods, and project reasons.

• The overall recap is presented and a report prepared for the JAD team.

JAD Advantages

• Allows key users to participate effectively
• Users will likely feel a sense of ownership
• Produces accurate system requirements, better understanding of common goals, and a stronger commitment to the success of the new system

JAD Disadvantages

• More expensive when compared with traditional methods; can be cumbersome if the group is too large

Rapid Application Development (RAD)

It uses a group approach similar to JAD.

• The end product is a New information system.
• RAD includes a methodology that features a four-phase life cycle, parallel to the traditional SDLC.
• It reduces cost and development time while increasing the probability of success.
• RAD relies on prototyping and user involvement, with prototypes modified based on user input.

RAD Objectives

• Reduce development time and expense
• Involve users in every phase of the system’s development
• Must have the right IT resources, skills, and management support

RAD Advantages and Disadvantages

• Helps quickly develop systems with significant cost savings.
• There is a lack of detail to emphasize strategic business needs and less time to develop quality, consistency, and design standards.

Agile Methods

• Attempts to develop a system incrementally, by building a series of prototypes
• Prototypes are adjusted to user requirements regularly.
• Developers revise, extend, and merge earlier versions into the final product.
• Emphasis is put on continuous feedback.

Agile Method Advantages

• It is flexible and efficient when dealing with change.
• Frequent deliverables constantly validate the project and reduce risk.

Agile Method Disadvantages

• Requires strong technical and interpersonal skills for team members
• A lack of structure and documentation can introduce risk factors.
• May be subject to significant change in scope.
• Models help understand the design of a system.
• They involve graphical methods with nontechnical language that represent the system at various stages of development.

Systems Analysts

• Results based on facts into build models
• Models are studied to determine whether additional fact-finding is needed.

Functional Decomposition Diagrams (FDD)

• Top-down representation of a function or process.
• Show business functions and how they are organized into lower-level processes

Business Process Modeling (BPM)

• It represents one or more business processes utilizing Business process modeling notation (BPMN)
• Models have a standard language; include shapes and symbols to represent events, processes, and workflows.

Data Flow Diagrams (DFD)

• Show how the system stores, processes, and transforms data.

Use Case Diagrams

• Represent the interaction between users and the system.
• Use Case Diagrams document the credit card validation use case.

Sequence Diagrams

• Show the timing of interactions between objects and when they occur

Interviews

• Determine the people to interview
• Establish objectives for the interview
• Develop interview questions
• Prepare for the interview
• Conduct the interview
• Document the interview
• Evaluate the interview

Step 1 - Interview stage

• Determine the people to interview by selecting the right people and asking the right questions.
• Decide on group and/or individual interviews.

Step 2 - Interview stage

• Establish objectives for the Interview by determining the areas to be discussed.
• List the facts that need to be gathered.
• Objectives depend on the role of the person being interviewed.

Step 3 - Interview stage

• Develop Interview Questions to avoid leading questions.
• Use open ended questions to encourage spontaneous and unstructured responses.
• Limit the response with Close-ended and Range-of-response questions used to verify facts on a numeric scale.

Step 4 - Interview stage

• Careful preparation is essential.
• Limit the interview to no more than an hour.
• Verify time, place, length, and topics via e-mail.
• Inquire if there are questions or documents, and ask the interviewee to have samples available at the meeting

Step 5 - Interview stage

• Conduct the Interview by developing a specific plan for the meeting.
• Begin by introducing yourself, describing the project, and explaining the interview objectives
• Practice engaged listening
• Allow sufficient time for the person to think about the question and answer.
• Summarize the session and seek confirmation after the interview.

Step 6 - Interview stage

• Document the Interview with minimal note taking.
• After conducting the interview record the information quickly, Send memo to the interviewee expressing appreciation for their time.
• Provide the date, time, location, purpose of the interview, and the main discussion points, so the interviewee has a written summary and can offer additions or corrections

Step 7 - Interview stage

• Evaluate the Interview by recording the facts obtained and trying to identify possible biases.
• Keep in mind that no matter how well prepared you are, some interviews are not successful because of Misunderstanding, and personality conflict could affect the interview negatively. Because of this, the interviewee might fear that the new system will eliminate or change roles and positions.

Other Fact-Finding Techniques

• Baseline documentation reviews to help someone understand how the current system should work. Observation is beneficial, as it provides a better perspective and understanding of the system procedures, though it should be planned in advance. Questionnaires and surveys must collect the right data and are usually traditional forms, fill-in forms, or forms from online survey websites designed to collect data.

Brainstorming sessions

• A form of gathering ideas and creating solutions within the system
• There is a structured and unstructured form

Interviews vs. Questionnaires

• The interview is more familiar and personal, though is known for being a costly and time-consuming process.
• Questionnaires are designed to provide input and suggestions in order to collect as much information as possible.

Sampling

• Ensures the overall population is represented accurately
• There are three sampling forms, Systematic, Stratified, and Random

Research and Documentation

• Utilize outside sources such as the Internet, IT magazines, and literature to expand on the system
• Use documentations to record information and use that to build your system

Data Flow Diagram (DFD)

• Analysts use graphical techniques
• DFDs shows the system transforms input data into information.

Data Flow Diagrams

• Depicts how data moves through an information system.
• It does not show program logic or processing steps.
• A set of DFDs provides a logical model that shows what the system does, not how it does it.

DFD Symbols

Four symbols represent processes, data flows, datas stores, and entities. There are 2 types,

Gane and Sarson:

Used in dataflow diagrams

• Processes, data flows, data stores, and external entities all have a unique symbol.

Yourdon:

• Used in data flow diagrams
• Processes, data flows, data stores, and external entities each have a unique symbol

Process Symbol

• It must have at least one in and output
• Contain the business logic that transforms the data.
  • Example: Apply Rent Payment, Calculate the Commission
  • In DFDs a process is also known as a black box
  • Has an identifiable verb

Data Store Symbol

• Identified using plural nouns or collective nouns, examples: Students, accounts receivable, products, grade book, passengers.
• In some cases, the data store has no input and data because they are already contain fixed data

Data Flow Symbol

• Symbol for a data flow is a line with a single or double arrowhead.
• It represents one or more data items Examples such as Student ID Number, Student ID, Name, Age etc.

Some things to avoid when designing your system

• Spontaneous Generation
• Black Holes
• Gray Holes

Entity Symbol

• Shows how the system interfaces with the outside world, they serve as the data origins or end points of data.
• Each Entity must be connected to a process by data flow.

Reminders to consider include:

• All flow lines must be labeled at all times.
• Large processes can be broken down into smaller components

Guidelines for Drawing DFDs

• Draw the context diagram so that it fits on one page; use the name of the current information system as the process name in the context diagram. Use unique names within each set of symbols; to not cross lines.
• Including more than nine symbols is a signal that the diagram is too complex. Give a reference number for each process. Ensure that the model is accurate as an output.

Creating a Set of DFDs

• Step 1: Draw the context diagram
• Step 2: Draw a Diagram 0 DFD include double headers as you wish. Functional diagrams are helpful for information.
• Step 3: Draw the Low Level Diagrams, level using the given standards such as the labels.
• There are also techniques given for balancing each attribute of the system.

Steps when drawing DFDs

• Uses leveling examples, uses series of detailed notes to describe
• Has an information system
• Exploding, partitioning, or decomposing

Explore the core principles of systems analysis, including team-based methodologies, fact-finding techniques, and data representation methods. Learn about user involvement, object creation, and the importance of understanding user needs. Also, understand Data Flow Diagrams.