The automation of design and sale of electronic and mechanical components is accomplished by allowing a user to design a plan for their electronic and mechanical component needs using specialized software. The software utilizes predefined models of components to aid the user in designing a system where all the components are compatible, even in cases where the components are made by different manufacturers. This is accomplished by creating a model for each proposed piece of equipment in the system, the model having properties and rules, wherein the rules define conditions and actions. Then an object is created for each piece of equipment in the system. Selections for values for the properties are received for each of the pieces of equipment. Any rules that have as a condition the properties for which value selections are received are executed. Finally, testing may be undertaken to determine if a proposed configuration is valid by examining results of the rule execution.