Cost estimation is an essential work for the efficient management of any enterprise .It gives very useful information for the preparation of financial accounts. The problem of estimating the cost of welding activities within industrial engineering projects can be attributed to the existence of a number of variables that affect this task, which renders it more complicated. As a result, it is necessary to develop mathematical models and find optimized solutions to estimate the costs of different welding activates, including direct and indirect costs. In addition, the difficulties in welding cost estimation can be overcome by the implementation of a computer program that calculates the direct and in direct cost of welding. Activities and compares the different welding methods in terms of efficiency time and cost. The program is expected to compare the different process and take the appropriates decision on how to implementation the welding activities, thus, several departments at factories and corporations will benefit from the inclusion of such program. The current study delivers a theoretical model that optimizes the cost of welding activates based on all variables involved in affecting the total costs .it also develops computer software, which is capable of accurately calculations welding cost and time. Furthermore, particular experiments are conducted to determine the deposition rate of welding metal in different position (vertical, flat).through experiments conducted, it was found that there are differences in deposition rate in different welding positions (vertical, flat).It was also found that more deposition metal weight is required in the vertical welding position compared with flat welding position. A vertical pressure vessel and horizontal fuel storage tank were taken case studies. Simple projects were considered in this study because of time consideration. Welding cost and project completion time for the selected projects have been calculated by using the developed computer program and the results obtained compared with those obtained manually by a nejem factory. The results revealed that the computer program developed in this study was very efficient in accurately calculating industrial project welding cost and completion time compared with manual methods of welding costs and time estimation .Finally, this research study concludes with proposing a number of recommendations which are of benefit to researches, factories and decision makers.it is highly recommended to use software program to calculate the welding costs of industrial projects and the time required to accomplished them, in addition to conduct more experiments to extract the deposition rate and compared different deposition rates for different welding position. Keyword: Welding, Cost Estimation, Welding Process, Welding Cost.