goal programming

One of the most important parts of the green supply chain management (GSCM) is the green supplier. The green supplier selection process has a vague nature. Therefore, specific approaches, such as fuzzy, are necessary during their evaluation. On the other hand, the choice of a coherent and integrated strategy is vital to achieve lean and green production. Accordingly, the present study aimed to select suppliers based on lean green production indicators by goal programming, fuzzy DEMATEL and quality performance expansion. The statistical population of this study consisted of personnel (managers, assistants and experts) with 16 managers and assistants and 46 experts. In this research, the Cochran formula (including error percentage of 5%) was used to determine the number of statistical samples. Accordingly, 53 experts from Pars Khodro Company participated as a sample (by simple random sampling method). In order to analyze the data, fuzzy DEMATEL methods, expansion of fuzzy performance quality and goal programming were used. According to the findings of the present study, continuous improvement to achieve lean green indicators is the main element of the production system at Pars Khodro Company. The important aspect of determining how much damage would be bestowed on the best supplier, so that it would be possible to determine the least amount of damage in sum, was reviewed in this section. In other words, the lowest possible losses are based on the suffering of the current  losses, the supplier and in which level of losses it has the most optimal status.

We have a huge civic project, includes several sub-projects, which are divided into activities. This project is a project to rehabilitate 550,000 hectares of agricultural land in the provinces of Khuzestan and Ilam. The project has been divided according to the plots of land. The Jehad in Tehran is managing the projects. They need project scheduling as well as resource levelling and "lot-sizing". Levelling and lot sizing are the most important issues in utilizing the limited resources. For determining the scope and the size of those sub-projects as well as their parallel activities, so far, many models have been proposed. However, the models are weak either in higher resource utilization or in solving numerically the problems. In this paper, our effort has been concentrated on developing scheduling, resource levelling, and lot sizing model, based on balancing utilization of resources, so that the real size civil project could be solved within an acceptable duration time. This paper proposes a goal programming linear model for simultaneous project scheduling and resource levelling. This model determines the best schedule of sub-activities (optimal "lot size" of each sub-activity) to reach the minimum amount of diversion of resources consumed from the number of resources available for the entire periods of the planning horizon. In fact, if the best "lot sizes" have been taken, then minimum fluctuation of the active resources is reached. The proposed model has been used to schedule a project with 87 activities. This project has been scheduled and, accordingly, the optimal volume (the "lot size") of sub-activities have been determined for each activity at any period of time. In this way, only 4 resources out of a total of 32 resources are in shortage. In contrast, the scheduling of this project, using the CPM, results in a shortage of 13 resources.