1.4 Implementation Q Flashcards
Describe purpose of system implement
To create a working computer system based on previously produced system design documentation
Explain what happens in pilot changeover method.
Some data from old system processed by new system.
New operate alongside old only processing part of the data.
Results compared.
Explain what happens in phased changeover
Some parts of system replaced by new system. In sequence. Remainder of system continues to operate using old information system.
Explain what Happens in parallel changeover method
Old and new system operate side by side (parallel) for short period of time. Results can be compared.
Evaluate the parallel changeover method (context given)
ADVANTAGES
supports comparison of results of processing w new and old.
Old system available as backup- event of new system failure- less risky.
Less stress for staff as have security of old. Can take their time learning new.
DISADVANTAGES
+ workload for staff- all items must be processed in duplicate.
Evaluate the direct changeover method (context)
ADVANTAGES
new running immediately.
No + costs w duplicate processing of data therefore cheapest method of installation.
DISADVANTAGES
No comparison of output between old and new.
No backup- event of failure of new- risky.
Have to transfer all data before old can be switched off.
Period of time where no system available.
Evaluate pilot changeover method (context)
ADVANTAGES
Data processed by old and new is available for comparison.
Staff from pilot departments can help with the training of other staff.
Only small part of business affected. Any issues identified.
DISADVANTAGES
cannot test efficiency of the system with larger quantities of data.
Cannot share data easily w rest of company using old.
Extra work for IT staff supporting 2 different systems.
Evaluate phased changeover method (context)
ADVANTAGES
Supports gradual installation of new system and staff training.
Less risk of whole system going wrong- only affect part.
DISADVANTAGES
if system failure occurs in the transitioned phase- no backup system available for staff.
Takes long time
As parts are used, users ask for changes- hold up next installation phase.
Compare and contrast pilot and phased changeover methods.
SINIKARITIES
both involve the old and new systems being used.
CONTRAST
pilot- one branch switches to new tried it out before launching it company wide, while rest stay with old. Branch that tries out new system may realise it doesn’t meet requirements and reject it. Then other branches may never switch over.
Phased- the new system will definitely be implemented one stage at a time. In sequence or order.
Explain the difference between user documentation and technical documentation
User documentation- intended for average user.
Not for programmers.
Can be hard copy, online or embedded.
Could include tool tips and video tutorials.
Provides the user with all the information they need to support them in the successful use of piece of HW OR SW
technical documentation- not intended for general user.
Aimed at computer professionals.
Describes how system was designed.
Describes how system works rather than what it actually does.
Main components of user documentation
Table of contents HW + SW needed How to install How to use main features Explanation of error messages Troubleshooting guide.
Main components of technical documentation
Module specific
Code for each module
Test plans and results
Explain why data conversion is necessary/ what is the purpose of data conversion
When a new computer system is out in place, data from the system it has replaced will need to be converted to work in the new system.
Could be paper based to computerised.
Could be one way if formatting/ storing data being changed to a different way eg ASCII TO UNI or 4 digit year format instead of 2.
Give two examples of data conversion
Input of data from paper based records to electronic format for storage on a database system.
The complete migration of an entire database from one application to another.
Explain why system maintenance is necessary
To make sure the system continues to run smoothly following implementation. Could be errors on code, night not fully meet requirements, requirements might change.
