Abstarct: For requirements of buyers to be met, manufacturers are urged to deliver products in accordance with specifications sought by customers. The theme of ‘production assurance’ has been proposed in a bid to cope with this demand as it analyzes system behavior and boosts its performance by integrating various operation indices ranging from availability, reliability, maintainability as well as supportability. Identifying functional behavior of these systems on the basis of failures, operation conditions as well as their share in undertaking the task of production plays a vital role in reducing the overall costs of production and would provide the possibility to compete in global markets. In the present study, parts of mining fleet of Sungun copper mine complex was chosen for development of operational production capacity using idea of production assurance. Sungun marks Iran’s second largest copper producer and is situated in Varzeghan in East Azerbaijan province. Production assurance remains as a function of system performance and is controlled by failures. Failures, in turn, comprise two major parameters including functional properties and environmental conditions. Required information for the first parameter was collected via up-time and down-time data of systems. Information for the second parameter was however obtained from operating environment conditions like surroundings, vibration and pressure not to mention operator skills which entered the analysis through risk factors or covariates. As the first step following collection of necessary data, functional behaviors of bulldozer, loader and dump truck subsystems were investigated in view of availability index without taking into account impact of environmental conditions and results revealed that repair status of loader subsystem was in critical conditions. Afterwards, reliability of a loader subsystem was evaluated in view of impact of conditions under investigation and the threefold difference in productivity, as compared to the case when impacts were ignored, revealed the undeniable effect of environmental conditions on the index. Furthermore, in order to investigate effects of risk factors on maintainability, a different part of the fleet was studies within the frxamework of a system which consisted of a loader and a bulldozer as well as two dump truck subsystems. Results indicated that possibility of minor and major overhauls for loader subsystems stood at 25 and 80 percent respectively while the figure would be 30 percent if impact of environmental conditions are ignored. In the next step, the notion of importance measurement was exploited to determine critical subsystems for the two broad cases of with and without considering impact of environmental conditions. For the case in which influence ambient conditions were ignored, a part of the fleet was selected within a fleet comprising a wagon drill, a loader, a bulldozer subsystem in additions to five dump truck subsystems. As the results reveal, enhancement of system availability requires improvement in accessibility of subsystems. Also for loader subsystem, upgrading of system reliability enjoys a higher priority as compared with its reparability. For the second case, that is importance measured while considering impact of environmental conditions, system reliability of a mining fleet was considered which consisted of two loader and eight dump truck subsystems. Results stated that the best option for improving reliability of the system was to promote that of loader subsystems. In the last part of importance measurement, availability of a system, comprising a wagon drill, a loader, a bulldozer and five dump truck subsystems, were investigated and results showed that any rise in system availability was subject to an upsurge in availability of loader and bulldozer subsystems. Then, the concept of spare part prediction as the main branch of supportability for tires were analyzed. To this end, an algorithm for predicting number of tires required for 100-ton dump trucks was offered which entailed system performance within frxamework of reliability without considering impact of environmental conditions. Calculations revealed that the higher the reliability of subsystem and the better its performance, the fewer tires will be needed. The issue can be seen in 3.2, 2 and 1.2 values of required number of tires per year for the lower, optimum and upper estimated limits, respectively. By entering impact of environmental conditions, time-dependent risk factors (dump truck modern and tire trademark) of dump truck tire data were divided into 12 laxyers and stratified Cox regression model was used. In these model axial, rainfall and temperature risk factors were found to be the most effective factors on behavior of dump truck tire failures and will consequently affect the number of spare parts required to a great extent. Maintenance was investigated as the second branch of supportability in a dump truck subsystem. The suggested method in this sector was reliability-baxsed preventive maintenance which aimed to maintain reliability at the level of 80 percent. Accordingly, reliability analyses of the subsystem were carried out with four reliability functions depending on whether maintenance was done perfectly, imperfectly and in presence of absence of environmental impacts and, subsequently, four types of preventive maintenance strategy were proposed. The last step was to analyze deliverability using results of the analysis of historical data of performance where impact of environmental conditions and production capacity of a system consisting of a wagon drill, a bulldozer, a loader and six dump trucks were studies. Overall results indicated the undeniable effects of environmental conditions as well as that achieving real outcomes was subject to inclusion of risk factors in calculations. The analyses proved loader and mine drill wagon subsystems as critical devices. Therefore, enhancement of reliability and reparability of these two subsystems must be put high on the agenda.