A2 ICT – Module 5

Information: Policy, Strategy and Systems

Module Overview

Module Overview

POLICY – a plan of action adopted by an individual or group [in this instance related to ICT]

STRATEGY – planning in the long term for the success of an organisation

SYSTEMS – a group or combination of interrelated, interdependent, or interacting elements forming a collective entity

14.1 – Policy and Strategy Issues

14.2 – Software

14.3 – Database Management Concepts

14.4 – Communication and Information Systems

14.5 – Networks

14.6 – Human Computer Interaction

14.7 – Human Computer Interface

14.8 – Software Development

14.9 – Software Reliability

14.10 – Portability of Data

Structure of Module 5Structure of Module 5

What is the difference between a ‘policy’ and a ‘strategy’?

POLICY

A policy is a document written to structure and outline the strategy to those that it affects and to those who must implement it.

STRATEGY

A strategy is devised at the relevant level of management and is a long-term plan of change and improvement for an organisation.

Policy and Strategy Issues

An Information StrategyWhat strategic elements should a policy contain?

STRATEGIC PLANNING

ISSUES

Consistency with business

priorities

Centralisation or decentralisation

?

Different user needs

Hardware and software choices

Planning IssuesConsistency

with business priorities

STRATEGIC PLANNING

ISSUES

Centralisation or decentralisation

?

Different user needs

Hardware and software choices

Centralisation or decentralisation?

Centralised Information

Systems Department

Other Departme

nt

Other Departme

nt

Other Departme

nt

Other Departme

nt

Other Departme

nt

Other Departme

nt

Backup Strategies Insurance against:

Accidental damage Equipment failure Deliberate damage

Frequency Data (to be backed up) Media

e.g. RAID Storage

Location

Backup Procedures Full Incremental Differential Grandfather – Father - Son

Software Acquisition ‘Off the shelf’ packages purchased

Customised Developed by “end user” Developed in-house External consultant Leased

Software Evaluation Criteria Functionality Compatibility Ease of use Support

Technical Documentation

Cost Speed Upgradability

Evaluation Report An introduction outlining purpose Methodology used to evaluate software The actual evaluation

Software capabilities System requirements Results of benchmark tests Upgrade facilities Compatibility with existing software

Recommendations Justification for the recommended purchase

Software Testing Alpha Beta Acceptance testing

Software Maintenance Perfective Adaptive Corrective “Laws” of software maintenance

Lehman and Belady 19851. The law of continuing change2. The law of increasing complexity3. The law of large program evolution4. The law of organisational stability5. The law of conservation of familiarity

Flat File Databases - Problems Data redundancy Data inconsistency Program-data dependence Lack of flexibility Data not shareable

Relational Databases Tables (entities), records, fields (attributes) Relationships links tables (Entity relationships) Normalisation Standard notation

Entity names are in CAPITALS Primary keys are underlined Attributes are shown in brackets, separated by

commas MEMBER(member no,name, address)

Entity Relationships One-to-one

one product has one barcode

one-to-many one company can have many branches

many-to-many many products can be sold in many

supermarkets

one one

one many

many many

Database Management Systems

This is a layer of software inserted between the applications and the data, which attempts to solve the problems of “Unproductive maintenance” and “Lack of Security”

Two features of DBMS are: Program-data independence Restricted user access

DBMS

CompanyDatabase

DatabaseManage-mentSystem

Salesprograms

Purchasingprograms

Financeprograms

Payrollprograms

Personnelprograms

DBMS - Risks One user could change data that is

used by every one. How is confidential data kept safe? What if the hardware fails?

DBMS - Administration

The DBA’s tasks include the following: Data storage, retrieval and update Creation and maintenance of the data

dictionary Managing the facilities for sharing the

database Backup and recovery Security

The Data Dictionary Contains information about the database

‘database about the database’ What tables are included

and the fields in them Name and description of each data item The characteristics of data items

such as length and data type Any restrictions on the value of certain fields Relationships between items of data Control information

such as who is allowed to access data. Which users have read/write privileges.

Client – Server DatabaseDatabase operated over a network Client sends query, server does processing, results

returned to client Consistency is maintained –

only one copy of database (on server) Client stations can update the server database Appropriate report can be held on client workstations Communications time between server and client is

minimised only results are sent back to client

An expensive resource available to a number of users

Distributed Database Several computers on a network each hold part

of the data Each computer cooperates to make data

available to the user May be necessary to sent requests and results

over the network to users Each computer may keep separate copy of

frequently used data Need to ensure that only latest data is used

Networks and Communication

Portability of Data & Standards

Human Computer Interface & Interaction