The value of simulators for testing automation system application software and training operators in the hydrocarbon and petrochemical industry is proven. However, users often make mistakes when specifying or implementing these systems that reduce their effectiveness. In this paper we will discuss practical, proven approaches to addressing the following simulation issues:

· Fidelity – what is it and how much does the user need.

· Dynamics – what makes a simulation dynamic and how does the user achieve good dynamics

· Integrity – how does the user ensure simulation system integrity and why is it important

· Testing – unique requirements for simulators used for application software testing

· Training – proven approaches to ensure good operator training results