3.5 - Systems Analysis

• System Lifecycle gives structure and allows a project manager to manage a project rather than reacting to problems as they arise
• Waterfall Model Key Features:

  • Stages are arranged in order and completed one by one
  • Developers cannot proceed to the next stage until the previous stage has been completed
  • Each stage ends with a deliverable handover document informing the next stage of development
• Advantages of the Waterfall model:

  • Problems are quickly identified in the early stages and thoroughly investigated in the design phase
  • Customers understand what the final product will look like as the system is defined in the early stages
  • Thorough documentation is produced at each stage, allowing progress to be tracked easily
  • Staff changes are unlikely to impact the future of the project as documentation allows new staff to pick up the system
• Disadvantages of the Waterfall model:

  • Customers often cannot define what they want or understand the capabilities of technology
  • It can be difficult to define what is required at the beginning of a project, leading to potential wasted development time
  • Difficult to identify problems that may occur due to work done in other areas of a system
  • Backtracking is required if there is a modification to the system or if a bug remains undiscovered in late stages of development
• Agile focuses on developing working software rather than documentation
• Agile Methodologies (Extreme Programming):

  • Focuses on communication between programmers/teams with clients/customers
  • Encourages straightforward solutions rather than complex ones
  • Encourages feedback and working in pairs
• Scrum focuses on regular iterations to create functional prototypes quickly

  • Fixed length iterations called sprints
  • Several teams work on the same project simultaneously with each team focusing on a different piece of functionality
  • Regular meetings called scrums
• Advantages of Agile:

  • Working software is produced at a much faster pace
  • Closer collaborations between stakeholders
  • Constant customer feedback ensures the product meets customer expectations
  • Changes can be made at any time
  • Makes integration of new technologies easy, especially on systems with a long development lifecycle
  • System can be used with some features missing
• Disadvantages of Agile:

  • Relatively new way of working which may not fit into the experiences of customers
  • Documentation can be neglected
  • Tracking progress is more difficult as progression is not linear
  • Requires cooperation from the customer to provide feedback
• Stakeholders are people or groups with an interest in the development of software, such as business employees, programmers, end users, and hardware suppliers
• Users must not be confused with customers; they are the people who will use the software on a daily basis
• Programmers are the people developing the system and are invaluable to system analysts as they can spot subtle issues with a system
• Project Managers are responsible for monitoring the progress of a project and ensuring it is completed on time
• System Analysts must find exactly what a customer wants and work closely with a company to create specifications for a piece of software that developers must meet
• Problem Definition is the process of identifying issues in a customer’s current system and finding solutions with a new project
• Feasibility Study ensures that a project is completable and desirable for the developing company and customer to develop the software

  • Economic Feasibility: ensures the project can be completed within a set budget and allows for reasonable profits
  • Time Feasibility: examines if a project can be completed within the set time frame
  • Technical Feasibility: examines if the development company has the skills to develop the desired product
  • Political Feasibility: examines the impact on a company’s reputation if a piece of software is developed
  • Legal Feasibility: examines if a project complies with legislation and potential liability
• Analysis, Requirements, and Designs start with the Fact Finding/Discovery Phase, aiming to find exactly what is required of a system and produce specifications for development

  • Methods include Observation, Questionnaires, Document Collection, and Interviews
• Advantages of Fact Finding/Discovery Phase methods:

  • Observation: picks up parts of the system not immediately obvious to customers
  • Questionnaires: can get a large number of different opinions
  • Document Collection: reliable and shows most of the data stored on the current system
  • Interviews: large amounts of information can be gathered quickly
• Disadvantages of Fact Finding/Discovery Phase methods:

  • Observation: some people feel threatened when observed and behave differently
  • Questionnaires: not all employees will complete them, responses can vary widely
  • Document Collection: may contain sensitive information and give a limited view of the system
  • Interviews: time-consuming, interviewees may not answer truthfully or be intimidated
• Testing involves giving software to end-users to identify bugs or needed improvements for the user’s experience

  • White Box Testing: tests the structure of the code
  • Black Box Testing: tests the program alongside the requirements
  • Alpha and Beta Testing: alpha builds are unstable, beta builds are close to the final product
  • End-User Testing: takes place before the customer purchases the system
• Documentation includes User Documentation and Technical/Maintenance Documentation

  • User Documentation: targeted guides teaching users how to access different features of the software
  • Technical/Maintenance Documentation: outlines how a system was created and the inner workings of each section of code
• Implementation is the process of installing a system at the client’s site

  • Direct Changeover: risky, involves swapping to the new system immediately
  • Phased Changeover: old and new system used simultaneously, introducing new features in steps
  • Pilot Changeover: small parts of a business use the system initially
  • Parallel Changeover: old and new system run side by side to minimize downtime