Introduction
The metropolis of Tehran and neighboring cities, especially Shahriar, have been the final destination of immigrants from many different parts of the country in recent years due to the attraction of the most economic, social, and welfare facilities. According to statistics, the growth rate of marginalization in Shahriar is higher than its normal value of about 7.8 percent, which has become the main challenge for urban and rural managers. This irregular and unplanned migration has created many problems and difficulties for rural and urban planning officials as well as the residents of this city in recent decades. The most important issue that Shahriar has faced in recent decades.The set of causal, background, and intervening factors, strategies, and consequences that are effective in the formation of marginalization in this region, and hence, the need for research, is as follows. Despite numerous studies and researchers' efforts to explain and identify the factors of marginalization, this challenge has not only not received serious attention from the authorities, but has also been responded to solely through emergency service programs, which are limited to providing development services. In this regard, by outlining the process of marginalization in the studied area, the present study can provide useful insights into the actions and thoughts involved in marginalization to economic analysts, managers, and policymakers from a theoretical perspective. Accordingly, the main research question can be posed as follows: What is the process of marginalization formation in the villages of the central part of Shahriar?
Materials and Methods
The present study was conducted with the aim of examining and explaining the process of marginalization in the settlements of the Central District of Shahriar County. Therefore, in terms of purpose it is applied, in terms of approach it is qualitative–quantitative and interpretive, and in terms of method it is exploratory and analytical. For data analysis, grounded theory, the Delphi method, and the one-sample t-test were used.
Results and Discussion
The findings showed that this phenomenon is the result of the interaction of three groups of factors: causal, contextual, and intervening. Causal factors include lack of awareness, excessive migration, and insufficient access to public services as primary driving forces. Contextual factors such as poverty, unemployment, inequality, social deprivation, and weak infrastructure provide the conditions for the expansion of marginalization. Intervening factors including incorrect urban policies, administrative corruption, weak law enforcement, lack of integrated management, weak supervision, and managerial multiplicity intensify and reproduce this process. The results of the two rounds of Delphi surveys with the participation of 35 experts showed that all extracted categories were confirmed with a high level of consensus and possessed conceptual stability and validity. In addition, the results of the one-sample t-test indicated that all influential factors had a mean higher than the average level and all played a statistically significant role in the formation of marginalization, particularly managerial factors such as managerial multiplicity and incorrect urban policies, which obtained the highest mean values. Finally, strategies such as balanced regional development, improvement of education, public participation, and reform of economic policies can contribute to reducing poverty and inequality, decreasing crime, improving quality of life, and reducing pressure on resources, thereby facilitating the control of this phenomenon and strengthening sustainable rural development.

Conclusion
Solving the current and future problems of Shahriar and creating a livable environment for the marginalized in this region requires, more than anything else, a single institution with sufficient power and authority. This institution must be able to coordinate and supervise the performance of all existing institutions involved in management to achieve growth and development goals within the framework of approved programs and plans. Therefore, management and coherence between management units are essential.