Developpement D’Un Modèle D’Estimation Des Coûts D’Assemblages Soudés[Developement of welding cost estimation model based on welding feature concept]

Estimating the manufacturing cost is a critical task with high importance to industrial firms. The cost estimating can drive bidding strategies, management of resources, production policies and other issues crucial to the economic success of the company. Essentially, cost estimation should be quick and accurate. There are three main approaches towards cost estimation: estimation based on past experience (variant cost estimation), estimation based on explicit cost computations (analytical method) and parametric cost estimation. However, the most accurate cost estimates are made using the analytical approach. Among the many methods for cost estimating are those based on knowledge bases, features, operations, physical relationships and similarity laws. The aim of this study is to estimate different cost for the specific field of arc welding. It deals with assembly modeling welding. To do this, we have proposed a new application of feature: welding feature and preparation feature. This concept is based on the decomposition of the product in features. The proposed model presents a combination of two variants approach cost estimation based on characteristics of product and on manufacturing activity of process: • First, we developed an analytical method in order to estimate the welding time by determining the weight of the weld and this for each feature. Besides, we estimate others consumptions: gas, electrode and electrical power. • Second, we used parametric cost estimation for cost formulation due to deferent “feature cost” which compose the process of welding: Edge preparation (chamfering, bevel machining, grinding etc.), welding. This concept inquires the appropriate choice of the indicator. We have developed a database with Microsoft Access in order to estimate cost welding which use our model. This application, named SOUDABASE, helps in estimating welding time and cost. It will allow a relative novice to understand the effects of welding variables on production costs. Finally, we tested SOUDABASE application with industrial examples and we released a comparative study with DEVISOUD application proposed by CETIM, Senlis France in order to validate our model.