1. Information: Policy, Strategy and Systems Module Overview
A2 ICT – Module 5
Information: Policy, Strategy and Systems
Module Overview

2. 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

3. Structure of Module 5 Structure of Module 5
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

4. Policy and Strategy Issues
What is the difference between a ‘policy’ and a ‘strategy’?
A strategy is devised at the relevant level of management and is a long-term plan of change and improvement for an organisation.
STRATEGY
A policy is a document written to structure and outline the strategy to those that it affects and to those who must implement it.
POLICY

5. An Information Strategy
What strategic elements should a policy contain?
STRATEGIC PLANNING ISSUES
Hardware and software choices
Consistency with business priorities
Centralisation or decentralisation?
Different user needs

6. Planning Issues STRATEGIC PLANNING ISSUES
Consistency with business priorities
STRATEGIC PLANNING ISSUES
Centralisation or decentralisation?
Different user needs
Hardware and software choices

7. Centralisation or decentralisation?
Centralised Information Systems Department
Other Department
Other Department

8. Backup Strategies Insurance against: Frequency Data (to be backed up)
Accidental damage
Equipment failure
Deliberate damage
Frequency
Data (to be backed up)
Media
e.g. RAID
Storage
Location

9. Backup Procedures Full Incremental Differential
Grandfather – Father - Son

10. Software Acquisition ‘Off the shelf’ packages purchased
Customised
Developed by “end user”
Developed in-house
External consultant
Leased

11. Software Evaluation Criteria
Functionality
Compatibility
Ease of use
Support
Technical
Documentation
Cost
Speed
Upgradability

12. 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

13. Software Testing
Alpha
Beta
Acceptance testing

14. Software Maintenance Perfective Adaptive Corrective
“Laws” of software maintenance
Lehman and Belady 1985
The law of continuing change
The law of increasing complexity
The law of large program evolution
The law of organisational stability
The law of conservation of familiarity

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

16. 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)

17. Entity Relationships One-to-one one-to-many many-to-many
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
many
many

18. 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

19. DBMS Purchasing programs Company Database Database Manage- ment System
Sales
programs
Finance
programs
Payroll
programs
Personnel
programs

20. DBMS - Risks One user could change data that is used by every one.
How is confidential data kept safe?
What if the hardware fails?

21. 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

22. 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.

23. Client – Server Database
Database 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

24. 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

25. Networks and Communication

26. Portability of Data & Standards

27. Human Computer Interface & Interaction