How much is it to develop a customised system?
This is a very common and interesting question but also hard to answer. The cost may be different even though it is developed for the same industrial. The cost is mainly depends upon the some factors listed below:
- Complexity (High): If the system requires different technologies to build up, like building web server, FTP server, or extra computer/network configuration, the cost will be high accordingly.
- sophiscated calculation(High):
It is not depending on how many buttons on the interface but how complex is the data being worked on.
- Similarity/ Software reusability(Medium):
The reusability is higher and the develop cost will be lower.
“Software reusability more specifically refers to design features of a software element (or collection of software elements) that enhance its suitability for reuse.”
- Data transfer and setup (Medium) In some cases, all the data in existing system is needed to transfer to the new system, eg from DOS program to Windows-based system. All these extra job will increase some extra cost.

Maintenance (Medium)﹕ System Maintenance are normally also related to the users’ literacy.

- Clear expectation (Medium)﹕ NO clear expectation will not have clear specification. Without a clear specification will somehow cause probelm under the process of development.

- Style/ Layout of the Interface (Low): All the windows-based program are having similar appearance. Changing colour of buttons, font size of any interface will not cause too much problem.

- Performance/ Response Time(Low,N/A): Normally the response time of windows-based system is much faster than web-based program.

- Amount of Data(Low,N/A): To deal with one row of data or ten thousands rows of data will make no difference of cost for development. 

- Number of users (low,N/A): The system is for multiple users, and can be accessed simultaneously.

- Time restriction (N/A): Once the system being built, it will have no restriction of time to use or number of users.