Business Information Systems: Chapter 11 Systems Design

Flashcards from Business Information Systems Chapter 11 on Systems Design to aid in exam preparation.

What is the definition of Systems Design?

The design phase of the lifecycle defines how the finished information system will operate.

What does the design specification define in Systems Design?

(a) The best structure for the application. (b) The best methods of data input, output and user interaction via the user interface.

Why is System Design important?

System design governs how well the information system works for the end-users in the key areas of performance, usability and security. It determines whether the system will meet business requirements and deliver the return on investment.

What are the aims of System Design?

To produce an appropriate design that results in a good-quality information system that: Is easy to use; Provides the correct functions for end-users; Is rapid in retrieving data and moving between different screen views of the data; Is reliable; Is secure; Is well integrated with other systems

What directly constrains system design?

The user requirements specification, and the hardware and software environment of implementation.

What is the distinction between analysis and design?

The distinction is often made between the logical representation of data or processes during the analysis stage and the physical representation at the design stage.

What are the two ways of approaching system design?

Top-Down Design and Bottom-up Design

What does Top-Down Design involve?

Specifying the overall control architecture of the application before designing the individual modules.

What does Bottom-up Design involve?

Starting with the design of individual modules, establishing their inputs and outputs, and then building an overall design from these modules.

What is Validation in system design?

A test of the design where we check that the design fulfills the requirements of the business users which are defined in the requirements specification and ask, ‘Are we building the right product?’

What is Verification in system design?

A test of the design to ensure that the design chosen is the best available and that it is error-free, asking ‘Are we building the product, right?’

What is Scalability?

The potential of an information system, piece of software or hardware to move from supporting a small number of users to a large number of users without a marked decrease in reliability or performance.

What are the major elements of system design?

Overall design or system design; Detailed design of modules and user interface components; Database design; User interface design; and Security design.

What does system or outline design involve?

Specifying an overall structure or systems architecture for all the different components that will make up the system. It is a high-level overview of the different components that make up the architecture of a system and how they interact.

What is Systems architecture?

The design relationship between software applications, hardware, process and data for an information system.

What does detailed or module design involve?

Considering how individual modules will function and how information will be transferred between them. It involves the specification of how an individual component of a system will function in terms of its data input and output, user interface and security.

What is included in Module design?

How the user interface will function at the level of individual user dialogues; How data will be input and output from the system; How information will be stored by the system using files or a database.

What are the functions of a database?

To enter, modify, retrieve and report information.

Define Database.

All information for one business application (normally made up of many tables). Example: sales order database.

Define Table.

A collection of records for a similar entity. Example: all customers of the company within the sales order database. Other tables in the database are product and order.

Define Record.

Information relating to a single instance of an entity (comprising many fields). Example: single customer such as Poole.

Define Field.

An attribute of the entity. Example: customer name or address for a particular customer such as Poole.

What are the three tables used for sales order processing database?

Customer, order, and product.

What is a Key field?

This is a field with a unique code for each record. It is used to refer to each record and link different tables.

What are Primary key fields?

These fields are used to uniquely identify each record in a table and link to similar foreign key fields (usually of the same name) in other tables.

What are Secondary or foreign keys?

These are used to link tables by referring to the primary key of another table.

What must Fields be defined in terms of?

Field name, Field data type, Field data size, and Field validation rules.

What is Normalization?

A procedure that is used to optimize the physical storage of data within a database. It involves simplification of entities and minimization of duplication of data.

What is the main purpose of data normalization?

To group data items together into database structures of tables and records which are simple to understand, accommodate change, contain a minimum of redundant data and are free of insertion, deletion and update anomalies.

What does a batch system involve?

Processing of many transactions in sequence. This will typically occur over some time after the transactions have occurred.

What does a real-time system processing involve?

Processing that occurs immediately data are collected. Processing follows each transaction.

What are the three main parts of User interface design?

First: defining the different views of the data such as input forms and output tables. Second: defining how the user moves or navigates from one view to another. Third: providing options for the user.

Name some Interface elements.

Forms, Views, Dialogs, and Menus.

What is (HCI) design?

The study of methods for designing the input and output of information systems to ensure they are ‘user-friendly’.

What are the four main attributes of security?

Authentication, Authorization, Privacy, and Data integrity

What are CASE tools?

Software that helps the systems analyst and designer in the analysis, design and build phases of a software project.

When an error is encountered the design will specify what?

Users should be prompted with a clear but not alarming message explaining the problem; The message should contain sufficient diagnostics that developers will be able to identify and solve the problem.