SG 10

System design

It is the specification of a detailed computer based solution.

Information systems design

It is defined as those tasks that focus on the specification of a detailed computer-based solution. It is also called physical design. Thus, whereas systems analysis emphasized the business problem, systems design focuses on the technical or implementation concerns of the system.

Model-driven design

A system design approach that emphasizes drawing system models to document technical and implementation aspects of a system.

CASE tools

It offer consistency and completeness as well as rule-based error checking.

Modern Structured Design

A system design technique that decomposes the system’s processes into manageable components.

Information Engineering (IE)

A model-driven and data-centered, but the process-sensitive technique for planning, analyzing, and designing information systems and IE models are pictures that illustrate and synchronize the system’s data and processes. The primary tool of IE is a data model diagram.

Prototyping

A small-scale, incomplete, but working sample of a desired system. Iterative process involving a close working relationship between the designer and the users.

Object-Oriented Design (OOD)

A techniques are used to refine the object requirements definitions identified earlier during analysis, and to define design specific objects.

Joint Application Development (JAD)

It is a technique that complements other systems analysis and design techniques by emphasizing participative development among system owners, users, designers, and builders.

Rapid application development (RAD)

A systems design approach that utilizes structured, prototyping, and JAD techniques to quickly develop systems.

Application Architecture

A specification of the technologies to be used to implement information systems.

Design the Application Architecture

The purpose of this first design task is to specify application architecture. An application architecture defines the Define technologies to be used by (and used to build) one, more, or all information systems in terms of their data, processes, interfaces, and network components.

Physical data flow diagram

A process model used to communicate the technical implementation characteristics of an information system. It is used to established physical processes and data stores (database) across a network.

Design the System Databases

The design of data goes far beyond the simple layout of records. Databases are a shared resource. Many programs will typically use them. Future programs may use databases in ways not originally envisioned. Consequently, the designer must be especially alternative to designing databases that are adaptable to future requirements and expansion.

Database schema

It is the structural model for a database. It is a picture or map of the records and relationships to be implemented by the database. It is optimized for implementation DBMS.

Design the System Interface

Once the database has been designed and possibly a prototype built, the systems designer can work closely with system users to develop input, output, and dialogue specifications.

Package Design Specifications

This final design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the computer programmer's activities during the construction phase of the systems development methodology. An specifications to guide programmers.

Update Project Plan

Now that we're approaching the completion of the design phase, we should reevaluate project feasibility and update the project plan accordingly.

Request for Proposals (RFP)

It is used to communicate requirements and desired features to prospective vendors. Several different vendors and/or products are candidates. They will respond with a proposal.

Request for Quotations (RFQ)

It is used when you have already decided on a specific product that can be acquired from multiple sources. They respond with a price quotation.

Hard-dollar costs

You will have to pay to the selected vendor.

Soft-dollar costs

An additional costs you will incur if you select a particular vendor (to overcome a shortcoming, etc.)

Decision Analysis

Make revisions in models to reflect purchased solution. Implement purchased solution. Integration problems lead to revised business requirements statements.

Design

A technical specification for a subset of programs to integrate purchased and built solutions.

Heading

This section usually includes the name and address of the business originating the form.

Identification and access

This section includes codes that may be used to file the report and gain access to it at a later date. This information is very important when an organization is required to keep the document for a specified number of years.

Instructions

This section tells how the form should be filled out and where it should be routed when complete.

Body

It is the middle of the form, which composes approximately half of the form. This part of the form requires the most detail and development from the person completing it. It is the part of the form most likely to contain explicit, variable data.

Specialty form

It can also refer solely to the way forms are prepared by the stationer.

Three clicks

This rule says that users should be able to get to the pages they need within three mouse or keyboard click.

Icons

These are pictorial, onscreen representations symbolizing computer actions that users may select using a mouse, keyboard, light pen, touch screen, or joystick. They serve functions similar to those of words and may replace them in many menus, because their meaning is more quickly grasped than words.

Systems design

It differs for in-house development, or build' projects, versus “buy” projects, where a systems software package is bought