David Wile’s (1996) synthesized HPT model presents two separate domains and paths of analysis to use when examining human performance. Wile focuses on elements both external and internal to the performer. He further subdivides the external domain into the categories of intangibles and tangibles, noting that each requires specific interventions. The model is unique in that it offers concrete solutions to varying performance problems and discriminates between interventions that are training solutions and those that are not. The simplicity of the diagnostic flow in this model makes it easy to take the first steps in solving a performance problem.
Wilmoth, F., Prigmore, C., Bray, M., HPT Models: An Overview of the Major Models in the Field. Performance Improvement 41(8).
http://www.sixboxes.com/_customelements/uploadedResources/HPTModels.pdf