Understanding Data, Information Systems, and Development Methodologies
Understanding Data and Information
1. Data and Information
- Data: Records of facts, events, or transactions. Data are the raw material used to obtain information.
- Information: Processed data that is useful to the recipient.
Having the right information is crucial for making the most appropriate decisions in each situation.
Systemic Approach to Problem Solving
2. Systemic Approach
The systemic approach begins by designing the entire system as a single black box, where only inputs and outputs are initially distinguishable. After identifying the system’s boundaries and its relationship with the external environment, the internal workings are described by opening the black box. Large internal components, or subsystems, are identified along with their interrelationships. The process continues by decomposing each subsystem into smaller components until the elements are simple enough to be fully studied without issues. This approach embodies the principle of thinking globally and acting locally.
Information Systems (IS)
3. Information Systems (IS)
An Information System (IS) is a formal set of processes that operate on a collection of structured data tailored to the needs of a company. It collects, processes, and distributes the information necessary for the company’s operations and for directing and controlling activities related to carrying out its business strategy.
- Data suited to the needs of the company.
- Daily operations, direction, and control activities require information.
- Alignment with business strategy.
Elements of an Information System
- Procedures and routines for work within the company.
- Information is the rationale of the system and must adapt to the people who operate it according to the company’s established work procedures.
- People or consumers of the organization:
- Enter information.
- Manage information in their activities.
- Use information.
The Development Cycle
The development cycle consists of a linear sequence of consecutive stages, where no stage begins until the previous one ends. The end of each phase generates a report describing what has been done and produces a plan for the next phase. This information is used by analysts and designers in the subsequent phase.
- Phase 1: Considered the most important phase. It defines the problem to be solved, establishes the project’s limits, and specifies the resources required.
- Phase 2: The feasibility study proposes several solutions to the overall problem, providing an idea of what the new system will be like.
- Phase 3: This phase involves a detailed analysis of the system, where analysts use common data analysis techniques to obtain information about the system.
- Phase 4: To design the new system, various tasks are performed. Designers must select the necessary equipment, specify new programs and changes to existing ones, and define new databases and modifications to existing ones.
- Phase 5: This phase is split into two smaller phases: development and implementation.
Problems of the Development Cycle
The development cycle has an important property: all activities are performed in a strict sequence. One phase must be completed before the start of the next and cannot be repeated.
The cycle specifies a system in descending order, with successive phases increasing the system’s detail.
In practice, some phases overlap. If an objective defined in the feasibility study cannot be achieved, it must be redefined. If errors are encountered during the implementation phase, it is necessary to redesign the system.
The cycles of problem-solving (linear loops) involve revisiting and replanning initial phases. To resolve errors, it is preferable to divide the problem into smaller parts and address them incrementally.
Development Methodology
A development methodology is a set of procedures, techniques, tools, and documentary support that helps developers create new software.
Components of a Development Methodology
- How a project should be divided into stages.
- What tasks are performed at each stage.
- What output is produced and when it must be produced.
- What restrictions apply.
- What tools will be used.
- How a project is managed and controlled.