Methods of conversion
Posted in Computing, Systems developmentWhen the final system is ready to go there needs to be a method of converting from the old system to the new system. This can be done in one of 4 ways.
Parallel conversion
Parallel conversion involves keeping the old system running alongside the new system for the first couple of weeks or months after the introduction of the new system. This means that any problems with the new system will not affect the continuation of the business. The problem with parallel implementation is that it costs more to run both systems and it also means data has to be entered twice which takes more time and is liable to errors.
Direct conversion
This involves taking the old system offline and putting the new system online within a day or over a weekend or holiday period. This is cheap but also quick, allowing the new features to be put to use immediately. However if there is a problem with the new system there isn't anything to fall back on.
Pilot conversion
A pilot conversion involves using the new system in only a small section of the company, for example a single department, branch or office. This allows any bugs to be found without a large effect on the company as a whole.
Phased conversion
This involves taking offline parts of the old system and replacing them with the corresponding parts of the new system. The actually conversion from the old parts of the system to the new parts may be either parallel or direct. This provides a compromise between parallel and direct conversion.