Role of the systems designer
The role of the systems designer is to define and develop systems which satisfy specified requirements of the user. These requirements have usually been passed onto them by the systems analyst. To achieve this, they must create both a logical and physical design.
A logical design is the conceptual blueprint of a software application, illustrating entities, relationships, rules, and processes. The aim here is to construct a relational schema that correctly and efficiently represents all of the information described by an entity-relationship schema produced during the conceptual design phase.
The physical design is concerned with the input and output processes of the system. The key issues here are how the data is input into the system and how this data is then verified. It also deals with how it is processed and displayed as output. It is here where they choose an appropriate database management system (DBMS) and establish the system security standards. They also decide on the interface design, data capture requirements, standards for printed report production and system navigation methods.
The physical portion of systems design can be divided up into three sub-tasks:
- User Interface Design
- Data Design
- Process Design
User interface design deals with how users add information to the system and how this information is then presented back to them by the system. Data design is refers to how the data is represented and stored within the system. The process design then deals with how data moves through the system, and with how and where it is validated, secured and transformed as it flows into, through and out of the system.
The systems designers utilise a number of other design methods also such as rapid application development (RAD) and joint application design (JAD). RAD is whereby a systems designer develops prototypes for an end-user to review and offer feedback. This is repeated until the end-user is satisfied with the final system. JAD is an evolution of RAD. Here the designer consults with a group consisting of the executive sponsor, subject matter experts and the managers of the system. The group collectively develops an agreed pattern for the design and implementation of the system.
Once these tasks have been completed they must pass their designs onto the programmers, who in turn convert the physical design specifications into a working computer code. The designers also continue to test the system to ensure it is working properly.
Sources: cathaldoyle.com & Definition of a logical design | logical design