Corrective: Correcting faults or bugs that did not reveal themselves during testing.
Adaptive: To make nessesary changes when something new is introduced into the organisation for example VAT change.
Perfective: Improve the performance of the ict system. i.e. adding a new feature to improve the speed.
Direct: A direct swap between the old system and the new system.
Risky, fewer resources (money, people equipment)
Parallel: The old system is run alongside the new system untill everyone is happy with the new system
Involves more work x2, time consuming, less risk involved
Phased: On module at a time is converted to the new system untill the whole system is transferred.
Only suitable for systems containing seperate modules, problems can be dealt with a module at a time.
Pilot: The system is testing in one branch at a time and then transferred to other branches in time.
Good for large organisations implementation is on a smaller and manageable scale. Takes longer.
User documentation, technical documentation
User documentation is there to help with any problems that occur.
Contains: hardware and software specification, how to load the software, frequently asked questions, how to back up data, save, print.
Avoid technical language
Backing up and closing down instructions
Technical documentation is produced to help systems analysts and programmers understand the technical workings of the system.
Contains: system design specification, data dictionary, screen layout designs, test plan, user interface designs, flowcharts.
Backup and recovery.
Disaster planning is needed: to minimise distruction, to get system working in shortest possible time. To ensure all staff know what to do.
Backup: regular, keep away from computer in locked fire proof safe, off site.
Restoration: running a mock to ensure oringinal files can be recovered using the backup.
Idnetifying risk: Potential risks: Viruses, fire, natural disasters, hacking, power failure, system failiure, theft, vandalism.
Risk ananysis: To make everyone aware of security threats to HW, SW and data.
Training: Mock tests should be run to make sure staff understand their role in the recovery process. Working together to get the system up and running in short time.
Contingency planning/disaster recovery
Disaster recovery/continguency plan
The purpose is to ensure the availability of essential resources ( staff, buildings power) and computer equipment if a disaster happened.
The plan covers the following:
total loss of computing equipment
loss of electricity, heating, air con
Loss of key employees
Loss of data or software
Loss of premesis holding ict equipment
Loss of maintenance or support services.
recovery methods, consequences of a disaster
Recover data from back ups
carrying out activties manually untill ICT services resumed.
Staff effected move to another location
Use an agreed third party stand by site.
Short and long term consequences
loss of network - productivity is lost, customers go elsewhere, resources tied up
Long term - Cash flow problems- invoices out late, annoyed customers, late delivery of orders, production delays caused by not having correct stock, stock shortage/overstocking because of lack of stock control.