The term domain expert is frequently used in expert systems software development, and there the term always refers to the domain other than the software domain. 
* A domain expert is a person with special knowledge or skills in a particular area of endeavor. An accountant is an expert in the domain of accountancy, for example. 
* The development of accounting software requires knowledge in two different domains, namely accounting and software.
* Some of the development workers may be experts in one domain and not the other.
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DomainExpert is a fancy term to describe people in a company with valuable functional knowledge, often called DomainKnowledge.  

It's a highly useful concept, one which the business community didn't value until a couple of years ago.  After firing numerous such people, and not realizing the productivity gains or cost decreases they expected, businesspeople asked why--and finally noticed what's obvious to many of us--employees with specific knowledge in some problem domain are worth their weight in gold.  Nowadays, you hear managers in corporations all around the world (who used to extravagantly claim that employees were all fungible commodities--sort of like cattle) speaking of DomainExpert''''''s in reverent tones.  

The words "nyah, nyah, told you so" somehow come to mind.  :)


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''I would have thought ExpertSystems, which appeared in the 1980s, would have driven all DomainExperts to oblivion by now. Whatever happened to ExpertSystems? Are these still used to capture key manufacturing/maintenance skills?''

You might also add: Whatever happened to ArtificialIntelligence, TheInternet?

The terms suffer from being broad, sweeping topics to which you might add: '''About What?''' and '''Anchored Where?'''

To take ExpertSystems to a cellular level, a RoboticManufacturingStation is managed by RobotController, programmed to act as a system to accomplish an action, and becomes such a system. In a sense, any ComputerProgram or subroutine belongs to ExpertSystems.
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PragmaticThinkingAndLearning discusses the limitations of ExpertSystems, as discussed by HubertDreyfus and others. In particular, the DreyfusModel of expertise shows that an expert may function worse when forced to stick to the rules.
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See also SubjectMatterExpert
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CategoryLearningMethods