Cost estimation for standard components and systems in the early phases of the design process

One of the most difficult tasks undertaken by the designer is to evaluate the cost of a design. This is a very important consideration in the design process, especially when the designer is trying to choose between alternatives, or optimising a particular solution. The designer must develop a design in order to fulfil the required performance characteristics as well as provide the appropriate quality at minimal cost. In order to better enable the designer to undertake this task, techniques for the cost estimation of a mechanical system from a description of the performance attributes for individual components is discussed. Three classes of engineering component are defined and methods for the cost forecasting of each class are proposed. These techniques are implemented in a system modelling tool, which provides a framework for multi-objective performance and cost optimisation of mechanical systems. It also enables the comparison of cost for various concepts at the early phases of the design process. The methods are validated through application to a range of mechanical components and an example case study is described.