Electromechanical products such as electrical toothbrushes and robots carry multitechnological characteristics, and functional operation of these systems is depended on the successful operation of all system components. There are interactions between electronic and mechanical components, software and other systems in complex products. These interactions such as heat, vibration, gravity, corrosion and electromagnetism can lead to functional and financial losses and failures of these kinds of products. The physical arrangement and mutual relation of subsystems and parts are very important to design reliable and robust systems. However, designing these products is complicated and time-consuming due to limitations on available expertise, tools, and methods. This paper presents a new product development approach proposed for integrating mechanical design with electronic design to improve design and manufacture of electromechanical products in terms of customer requirements, reliability, structural integrity, weight, cost and time. This approach has been implemented in a Delphi based environment integrated with a CAD system. It assists in evaluating complex systems as far as parts relation and their possible effects on each other, costs, weight and physical constraints are concerned in the early design process. This helps the designers to avoid design iterations, and minimize the likelihood of failures and rapidly develop reliable complex products subject to given constraints.