How to Build a Business Rules Engine

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An issue with business rules engines that cannot be dismissed is the problem of what

to do if a user suspects something is wrong. In traditional systems development pro-

jects there is a team of IT professionals that, in theory at least, can be called upon to

help to investigate and correct problems. With purchases of packaged software, there

is often a provision for some kind of after-sales support.

Business engines are different. Problems can arise because of the logic that users

themselves have defined. Of course, there can also be problems with the core func-

tionality of the engine itself, but these are much rarer because if code generation does

not work, it is usually immediately obvious—for example, when the generated code

cannot be parsed ...