ICT Class Eleventh Meeting

Development and Testing,

Implementation

A. DEVELOPMENT AND TESTING

1. Development Stages

• File structure needs to be finalized if the system contains file. 
• what type of data is being stored in each field
• length of each field
• which field will be the key field
• how the data files will be linked
• etc.
• After file structure is finalized, system needs to be tested so that it is robust when the system goes live.
• There are 2 ways in which data could be correctly placed in files: 
• validation routine
• ensure they do trap unwanted data 
• to make sure any data transferred from a paper-based system to an electronic system has been done accurately.
• verification method
• How these are used to interface with the final system now needs to be identified.
• How these devices are used with the system when it is implemented needs to be finalized if a special hardware is needed. Therefore, testing strategies are needed to ensure that the system can work well in any type of condition.

2. Testing Strategies

• Once development stage is done, testing strategy for the entire system needs to be done, although a single module can work well. This is to ensure the system will work well.
• These strategies will lead to improvements in many aspects, thus it will be very time consuming. However, these improvements are very essential so that the system can work at its best.
• There are 3 types of data testing. For example, the field is dd/mm/yyyy and that they have to be in numeric form
• normal: acceptable/valid data (month 1-12)
• extreme: at limits of acceptable/valid data (2 months (1 or 12))
• abnormal: outside the limits of acceptable/valid data that will be rejected
• negative numbers 
• value >12
• non numeric data
• non integers value

B. IMPLEMENTATION

• Implementation needs to be done once testing strategies are done.
• Implementation is called changeover for the whole system.
•  Changeover can be done in some ways:
• direct: stop the system and change it overnight to a new system
• advantage: immediate, reduced cost and less malfunction
• disadvantage: can be disastrous
• parallel running: both old and new systems are run together
• advantage: old system as back up, staff training gradually
• disadvantage: more expensive than direct
• pilot implementation: new system is introduced to a part of the company
• advantage: only one part of the company is affected, faster staff training, less expensive than parallel running
• disadvantage: more expensive than direct
• phased implementation: new system is introduced gradually in every part
• advantage: failure is not disastrous, may ensure system works properly
• disadvantage: more expensive than direct