Journal of Quality Engineering and Management

Abstract Purpose: This paper examines how blockchain technology can improve reliability and operational performance in hospital pharmaceutical supply chains with a focus on inventory variability and responsiveness to demand.
Methodology: A system dynamics model of a three-echelon chain (manufacturer–distributor–hospital) is developed. Two information-sharing scenarios are compared: a traditional setting with centralized, delayed information and a blockchain setting with real-time, decentralized data sharing.
Findings: Results indicate that blockchain adoption enhances behavioral stability, reduces the persistence of hospital backlog, and shortens mean delivery lead time. Specifically, mean lead time decreases by ~15.1% and mean hospital backlog decreases by ~15.8% (both statistically significant). However, the difference in mean hospital inventory is not significant; stability improves, with inventory SD decreasing by ~21.5% and lead-time SD decreasing by ~10%. Taken together, these effects strengthen service reliability and overall supply-chain performance.
Originality/Value: By integrating blockchain-based decentralized data sharing with system dynamics modeling in the hospital pharmaceutical context, this study provides quantitative evidence of how transparency supports quality-oriented supply chain management.

Abstract Purpose: In today's world, the role of the economy in shaping business models and the power of nations is highly significant. Exports play a vital role in enhancing productivity and economic development, particularly in developing countries. The automotive industry, as a key sector, contributes considerably to this process. This study aims to identify the key influencing variables on non-oil exports and explore how they affect productivity growth and export improvement.
Methodology: This research employs a system dynamics approach to model the interactions among key economic variables. The study utilizes VENSIM software to simulate the system dynamics model of the automotive industry and non-oil exports. Causal loop diagrams and stock and flow diagrams were developed to analyze the relationships.
Findings: The main variables analyzed in this study include exchange rate, inflation, productivity, and competitiveness. The developed model was validated and tested under various scenarios. Results indicate how changes in these variables impact productivity and the performance of non-oil exports in the automotive industry.
Originality/Value: This study offers a dynamic model tailored to the automotive sector in developing economies like Iran, where over-reliance on oil has led to inefficiencies in other export sectors. The model helps policymakers and industry stakeholders understand complex interactions and make informed decisions to boost non-oil exports and overall productivity.

Abstract There are many factors and variables that affect the reliability of organizations equipment that neglecting them may cause irreparable damage to organizations. Despite the importance of high reliability of equipment on the profitability of organizations, so far no research has considered the factors affecting it simultaneously and together. Because the relationship between these factors has a lot of dynamics and feedback, system dynamics is a good tool for analyzing the equipment reliability. The purpose of this study is to create and develop a new way to evaluate and improve the reliability of equipment of one of the most important industries in the world using the system dynamics approach in a 5-year horizon. In this regard, first, the key variables affecting the improvement of reliability, identification and their relationships in the form of accumulation and flow diagrams are completed and simulated in vensim software. Then, after creating a flow-accumulation diagram, suitable scenarios for improving performance are discussed. The validity of the model was also assessed by three tests of reference behavior reconstruction, limit behavior and sensitivity. Simulation results indicates that by implementing policies to improve staff training, allocation of resources to preventive maintenance, etc., the reliability of equipment is significantly increased and this will increase the sales and profits of the organization and managers should pay more attention to these variables. 

Abstract Privatization is considered as an approach to help organizations and corporates to achieve high efficiency in developing countries. Therefore, the way it affects the corporate performance is of great importance, because privatization and organizational excellence are so complicated due to feedback relationships, time delays, and dominant non-linear relationships. Moreover, the dynamics of the privatization’s effects on organizational excellence over time should be analyzed using a system dynamics approach in order to examine the effectiveness of privatization so that it can help corporates to make appropriate decisions and invest on the privatizations aspects with highest impact on organizational excellence. Privatization has not analyzed using the system dynamics approach in previous studies. Thus, this study aims to analyze and model the privatization’s effect on corporate performance using the system dynamics approach and EFQM excellence model in five stages in the National Iranian Drilling Company. After the statement of the problem, the key variables are identified and the time horizon is determined. Then, the dynamic hypothesis is presented and the structure of a causal loop diagram is depicted. The surface and flow maps are also explained and the model is simulated. Afterwards, the validity of the proposed model is examined based on validation tests. Finally, by analyzing the sensitivity of the model variables, designing and evaluating policies at the National Iranian Drilling Company are dealt with. Analyzing the impact of privatization on organizational excellence creates a set of advantages for the company using the dynamism systems, the most important ones are: simulating the effects of affective factors on the results; implementing "what if" to analyze the scenarios and potential. future threats; The ability to visually performance the relationship between privatization and organizational excellence; reduce the risk of executive programs by simulating and examining the consequences of different scenarios before implementing the dynamic model; and considering the time reliance between cause and effect. The effects of any changes can be simulated before practical application by using the proposed model in a virtual environment, and decision can be made by complete knowledge of all aspects. 
 
 
 

Abstract Due to the lack of water in the current era and the support of governments in replacing worn-out water transmission lines, the polyethylene pipe industry has become one of the attractions of interest for investors. But one of the concerns of the community is the quality of these pipes. Therefore, in the present study, the effect of quality management system on the quality of polyethylene pipes is investigated using system dynamics. The case study of this research is one of the companies in Kerman Pipe Manufacturing Industry. In this article, using the opinion of industry elites, the necessary variables were identified and causal diagrams and state and flow diagrams were drawn using Wensim software. The results of the analysis showed that when implementing the quality management system, all organizational units should be coordinated with each other and the role of management in it is very key so that any management negligence causes poor product quality, reduced customer satisfaction and consequently reduced The amount of product sales and waste increases and eventually the organization is in a state of liquidation, bankruptcy and doubling.