فهرست مطالب

مدیریت تولید و عملیات - سال یازدهم شماره 1 (پیاپی 20، بهار 1399)

مجله مدیریت تولید و عملیات
سال یازدهم شماره 1 (پیاپی 20، بهار 1399)

  • تاریخ انتشار: 1399/02/01
  • تعداد عناوین: 6
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  • مهدی نخعی نژاد*، نسیم مومن شاد صفحات 1-22

    مسئله پورتفولیوی پروژه به انتخاب زیرمجموعه ای از پروژه های پیشنهادی در سازمان توجه می کند. یکی از اهداف مدیریت پورتفولیوی پروژه، کاهش ریسک های موجود در فرایند انتخاب پورتفولیو است. در دنیای واقعی، ریسک های پروژه به ندرت، مستقل هستند و معمولا درجه ای از روابط متقابل دارند که با لحاظ کردن این تعامل ها، ارزیابی صحیح تری درباره مهم ترین ریسک های تاثیرگذار در موفقیت پروژه به دست می آید. در این پژوهش، براساس طبقه بندی «هزینه- زمان- کیفیت»، 11 نوع ریسک با جنبه منفی، شناسایی شدند تا تقابل پروژه ها به ازای ریسک های تاثیرگذار بررسی شود. با توجه به روابط متقابل ریسک های پروژه، این پژوهش برای اولین بار، روابط متقابل سه گانه این ریسک ها را برای کشف دقیق تر تاثیر عوامل بر یکدیگر شناسایی کرده است. در این مقاله با بررسی ریسک تک پروژه، از رقابت تک پروژه هایی که میزان ریسک آنها بیشتر از حد مجاز است، در پورتفولیو جلوگیری شد؛ اما آثار متقابل جفتی و سه گانه پروژه ها براساس معیارهای اثرگذار ریسک سبب شد علاوه بر میزان ریسک، از کنار هم قرارگرفتن پروژه هایی که موجب هم افزایی ریسک در پورتفولیو شدند نیز جلوگیری شود. درنهایت، برای ارزیابی اعتبار پژوهش، الگو به صورت دقیق با برنامه ریزی خطی عدد صحیح با دو هدف «بیشینه سازی نرخ بازگشت سرمایه» و «بیشینه سازی تعداد پروژه های پورتفولیو» و محدودیت بودجه بررسی شد. نتایج نشان دادند در نظر گرفتن اثر متقابل جفتی و سه گانه به جای در نظر گرفتن اثر متقابل جفتی به صورت مجرد، پاسخ های متفاوت و بهتری ارایه می دهد.

    کلیدواژگان: پورتفولیوی پروژه، ساختار شکست ریسک، اثر متقابل سه گانه
  • سید حسین رضوی حاجی آقا*، یوسف محمدی، شیده سادات هاشمی صفحات 24-43

    با توجه به رشد جمعیت شهرنشین و اهمیت زمان و هزینه در جوامع امروزی، سیستم های مترو با مسئله افزایش زیاد تقاضا و به دنبال آن، با افزایش زمان انتظار مسافران مواجه شده اند که مدیریت آن، دغدغه شرکت های مترو محسوب می شود. با توجه به محدودیت تعداد قطارها و تجهیزات در خطوط مترو و هزینه بر بودن افزایش آنها برای کاهش زمان انتظار مسافران در ایستگاه های تقاطعی، در این مقاله سعی شده است کاهش زمان انتظار مسافران از طریق الگوهای بهینه سازی ای انجام شود که غالبا هزینه ای را به سیستم مربوط تحمیل نمی کنند و ضمن کاهش زمان انتظار مسافران، ضعف های پژوهش های پیشین در این زمینه را نیز پوشش دهد. پژوهش حاضر، ضمن بررسی همه ایستگاه های تقاطعی و نیز کل ساعت های بهره برداری از مترو، الگوی بهینه سازی ای معرفی می کند که زمان انتظار مسافران در ایستگاه های تقاطعی خط 4 متروی تهران را به میزان 40 درصد کاهش می دهد.

    کلیدواژگان: زمان انتظار مسافران، ایستگاه های تقاطعی، الگوهای بهینه سازی، مسافران تقاطعی
  • محسن شیخ سجادیه*، مهسا بهمنی تبریزی صفحات 45-69

    امروزه، تعامل بلندمدت با تامین کنندگان در زنجیره تامین به فعالیت کلیدی سازمان ها تبدیل شده است و شرکت ها می کوشند به کمک آن، قابلیت های خود را بهبود بخشند. بر همین اساس، با توجه به محدودبودن تامین کنندگان توانمند، پیشرفت های مستمر تکنولوژیکی و نیازهای جدید بازار، لازم است لیست کوتاه تامین کنندگان هر سازمان گسترش یابد که فرایندی زمان بر و پرهزینه است؛ بنابراین توسعه قابلیت های رقابتی تامین کنندگان، راهکاری برای ایجاد منافع مشترک برای تمامی اعضا خواهد بود؛ اما جایگاه مناسب ارتقای تامین کنندگان کجاست و مقدمه آن چیست. در این پژوهش، مدلی فرایندی به همراه نرم افزار توسعه تامین کنندگان در حوزه پیمانکاری، با استفاده از الگوهای کیفی و مدل های پشتیبان تصمیم، همسو با پایداری زنجیره تامین معرفی شد. بدین منظور در کنار عوامل رشد، الزام های مشتری و صاحبان منافع در ابعاد زیست محیطی، اجتماعی و اقتصادی گنجانده شد. برای رسیدن به چنین دستاوردهایی، از روش هایی نظیر سرمایه گذاری، ارتقای اهداف کلیدی عملکرد و آموزش بهره گرفته شد. برای ارزیابی مدل پیشنهادی، ده تامین کننده واجد شرایط بهبود شرکت کنگلومرای پیمانکاری در حوزه های مختلف در ایران شناسایی و در هفت ماه در سه بخش شناخت، توسعه و پایش، و اجرا تحلیل شد. با توجه به نتایج، اعتبار مدل و نرم افزار در پنل های خبرگی پایش و تایید شد. از نوآوری های این پژوهش می توان به پیاده سازی هم زمان سه مرحله مدل در قالب مدلی یکپارچه اشاره کرد. محدودیت های این پژوهش، چالش در جلب مشارکت تامین کننده و اجازه ورود کارفرما به جزییات و طولانی شدن اجرای برخی اقدامات بهبود بوده است.

    کلیدواژگان: توسعه و بهبود تامین کننده، ارزیابی تامین کننده، زنجیره تامین پایدار
  • جعفر باقری نژاد*، مهدی بشیری، زهرا عابد پور، الناز سلطانی صفحات 71-87

    مسایل مکان یابی هاب در پی یافتن مکان بهینه تسهیلات هاب و تخصیص نقاط تقاضا به هاب ها برای پاسخگویی تقاضاها بین زوج مبدا - مقصد است. افزایش روزافزون سرعت تغییرات در ساختار هزینه و تقاضا، خیلی اوقات سازمان ها را برای ایجاد دوباره شبکه مجبور می کند. مسئله این پژوهش «مکان یابی هاب چنددوره ای با تخصیص تکی و محدودیت ظرفیت (DCSAHLP)» نامیده و یک مدل برای آن پیشنهاد می شود. در مسئله بررسی شده، تصمیمات مرتبط با مکان یابی و تخصیص در یک شبکه هاب بررسی می شود. هم چنین این موضوع که برای بازکردن هاب پیمانکاران مختلف وجود دارد، یا اینکه هاب ها بعد از انتخاب پیمانکار دارای طول عمر مشخص هستند و در انتهای این طول عمر می توانند بسته یا بازسازی شوند، بررسی می شود که مسئله را پیچیده تر می کند؛ در عین حال مسئله را به مسایل دنیای واقعی نزدیک تر می کند. در این مسئله سطوح ظرفیت و بازسازی چندگانه نیز در نظر گرفته شده است. درانتها از مجموعه مثال های عددی تغییریافته AP در اندازه های مختلف برای ارزیابی عملکرد مدل ارایه شده بهره گرفته شده است. نتایج حاصل از مقایسات نشان دهنده کارایی روش فراابتکاری ژنتیک است. همچنین مدل ارایه شده در این پژوهش نسبت به مدل های پیشین ارایه شده برای این مسئله از نقطه نظر هماهنگی و منطبق بودن با شرایط دنیای واقعی کارایی بیشتری دارد.

    کلیدواژگان: مکان یابی هاب چنددوره ای، تقاضای پویا، ظرفیت چندگانه، طول عمر هاب، بازسازی هاب، الگوریتم ژنتیک
  • کریم ابراهیمی، عادل آذر*، علیرضا چیت سازیان صفحات 89-109

    شناسایی شاخص های کلیدی در چارچوب مدلی علمی برای اصلاح و بهبود کیفیت خدمات دولت الکترونیک، از مهم ترین دغدغه های سیاست گذاران و کارورزان دولت الکترونیک است. در پژوهش پیش رو، پژوهشگر ضمن شناسایی معیارهای کلیدی کیفیت خدمات دولت الکترونیک با جست وجو در مبانی نظری مرتبط و توزیع پرسش نامه در میان 11 نفر از خبرگان و متخصصان حوزه مدیریت کیفیت، مدیریت دولتی، سیاست گذاری، فناوری اطلاعات و دولت الکترونیک، که از روش گلوله برفی انتخاب شدند، مدلی برای سنجش کیفیت خدمات دولت الکترونیک براساس رویکرد ترکیبی مدل سازی ساختاری تفسیری (ISM) و دیمتل تدوین کرده است. پژوهشگر با استفاده از ISM به معماری و مهندسی شاخص های کلیدی در بهبود کیفیت خدمات دولت الکترونیک و درنتیجه، تدوین مدل نظام مند جامعی و شناسایی تاثیر یک شاخص بر دیگر شاخص ها و از رهگذر دیمتل، میزان کمی تاثیر مستقیم و غیرمستقیم شاخص ها بر یکدیگر را محاسبه کرده است. مدل نهایی، نشان دهنده شاخص های سنجش کیفیت خدمات دولت الکترونیک شامل اعتماد مشتریان، کارایی، قابلیت برقراری ارتباط با مشتری، انجام دادن درست خدمات در بار اول، تنوع خدمات، دسترسی به خدمات، قابلیت ردیابی خدمات، پشتیبانی خدمات، تعامل پذیری، زیرساخت، جبران مالی، متناسب سازی، تضمین کیفیت و مدیریت شکایت ها و تاثیر و تاثر آنها بر یکدیگر است.

    کلیدواژگان: دولت الکترونیک، کیفیت خدمات، مدل سازی ساختاری تفسیری
  • اسماء بختیاری توانا*، مسعود ربیعه، مهدی اسماعیلی صفحات 111-132

    به کارگیری هم زمان اصول پایداری و تاب آوری در فرایند انتخاب تامین کننده و تخصیص سفارش، نقش بسیار مهمی در دستیابی به پایداری و تداوم فرایندهای کسب وکار در شرایط وقوع اختلال ها دارد. در این پژوهش، رویکردی ترکیبی، شامل ارزیابی و رتبه بندی تامین کنندگان براساس معیارهای پایداری و مدل سازی مسئله انتخاب تامین کننده پایدار- تاب آور و تخصیص سفارش تحت ریسک های اختلال معرفی می شود. درحقیقت، برای تعیین امتیاز پایداری تامین کنندگان، یکی از تکنیک های تصمیم گیری چندمعیاره (VIKOR) به کار می رود که نتایج حاصل از آن، پارامتر ورودی برای مدل ریاضی است. مدل ریاضی پیشنهادی از نوع برنامه ریزی تصادفی دومرحله ای با هدف حداقل سازی هزینه کل و بیشینه سازی عملکرد پایداری در شرایط اختلال است که با استفاده از روش محدودیت اپسیلون حل و برای بررسی اثر تغییر پارامترها بر نتایج نهایی، تحلیل حساسیت نیز انجام می شود. همچنین برای نشان دادن عملکرد مدل پژوهش، از موردی مطالعاتی (زنجیره تامین ایران خودرو) استفاده می شود. نتایج نشان می دهد با افزایش ضریب اهمیت عملکرد پایداری در زنجیره تامین، ارزش کلی فرایند تامین در زمان اختلال ها افزایش می یابد و منبع یابی چندگانه و استفاده از ظرفیت منعطف تامین کنندگان، یک استراتژی موثر تاب آور برای کاهش شدت اختلال هاست.

    کلیدواژگان: انتخاب تامین کننده، تخصیص سفارش، پایداری، تاب آوری، ریسک اختلال، برنامه ریزی تصادفی
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  • Mahdi Nakhaeinejad *, Nasim Momen Shad Pages 1-22
    Purpose

    The project portfolio problem proceeds to choose a subset among the proposed projects in organization. One of the purposes of project portfolio management is the reduction of the available risks in portfolio selection process. In real world, the project risks are rarely independent, and generally have a degree of interaction. By considering this interaction the more accurate evaluation of portfolio selection can be achieved. The purpose of this study is to provide a framework for selecting project portfolios by considering the triple interaction between projects for the first time using the correlation coefficient and the theory of cross-information for the risk factors affecting them.

    Design/methodology/approach

     First, this research identifies the most critical risks based on the literature review, project management body of knowledge and the relevant experts' opinions. Then, a questionnaire was distributed among 30 experts to quantify the identified risk criteria. The identified risks that are included 11 risks are in the categories of “technical”, “external”, “organizational” and “project management”. Then theses risks are placed in to the “cost”, “time” and “quality” classification. By considering the individual project risk, the projects which their risks were higher than the allowable limit, were not able to compete in the portfolio. Also, the pairwise and triple-wise interaction of the projects based on effective criteria caused that the projects which provoke risks synergies in the portfolio to be prevented from being together. By analyzing risks, the pairwise interaction effects between projects are calculated using Spearman's correlation coefficient and for the first time the triple interaction effects between projects are calculated using theory of cross-information to discover more precisely the effect of factors on each other. Finally, the modeling in the form of a case study based on integer linear programming along with two goals, “maximize IRR” and “maximize the number of projects in the portfolio”, are accurately assessed to evaluate the research validity.

    Findings

    The problem of project portfolio is the selection of a subset of proposed projects according to the strategic goals of the organization and the associated constraints. This paper provides a framework for selecting project portfolios by considering the triple interaction between projects for the first time. The results show that considering pairwise and triple-wise interaction instead of individual pairwise interaction comprise different answers. This result leads to discovering the relationship which can not be identified just with the pairwise interaction.

    Research limitations/implications

    In this research the risk criteria are considered generally, while, in specific projects it can be used specific criteria. Using the meta-heuristic methods when the problem dimensions are increased is another area for future research. In addition, fuzzy methods and stochastic subject in order to quantify the risk criteria could be considered. Besides, this paper considers risks with negative aspect for project portfolio selection, while, in future research suggested that the risks with aspect of the positive are considered as well.

    Practical implications

     One of the most important application of this paper is for project-oriented companies that are involved in doing multiple projects simultaneously. The results of this paper are useful for these companies for risk reduction in selecting and performing their projects.

    Social implications

    This paper considers the most important risks affecting project execution. These risks include external risks of organization as well as internal and technical risks of organization. So, the paper helps organizations for the most appropriate selection of projects that could have benefits for organization and also society.

    Originality/value

     In the literature, there are various methods that researchers have considered for risk management. Most of these studies don’t consider interactions between projects or simply they considered only pairwise interaction. The main purpose of this study is to consider a higher level of interactions that is triple interactions that not considered in the literature. The results show that considering triple-wise interaction instead of individual pairwise interaction comprise different and better results.

    Keywords: Project portfolio, Project management body of knowledge, Triple-wise interaction
  • Seyed Hossein Razavi Hajiagha *, Yousef Mohammadi, Shide Sadat Hashemi Pages 24-43
    Purpose

    Regarding urban population growth and importance of time and cost in the societies of today, subway systems have faced with demand increase and passengers waiting time have prolonged. In urban transportation systems especially in subways, the passengers waiting time influences the society satisfaction deeply. Since the emersion of rail network, time and scheduling as important challenges have been emerged. Then the periodic train planning as one of the best solutions was introduced to decrease passenger waiting time, reduce travel length, and increase transportation safety. This challenge should be solved by subway managers. Due to the limited number of trains and equipment on subway lines and increase of their cost-effectiveness in reducing passenger waiting times at intersections, an attempt has been made in this paper to reduce waiting time using optimization models that often do not impose costs on the system. In addition, another aim of this paper is to fill the existing research gap in this area.

     Design/methodology/approach

     This paper aims to calculate the weights of intersectionsstations in order to minimize the passenger waiting time through goal programming (Khalili Damghani et al. 2015; Mosadeghi et al. 2010). Many studies have been done on train scheduling and transportation mathematical modelling all around the world (Moghaddam and Mahlooji, 2017; Sadeghieh and Dehnavi-Arani, 2019). The aim of this paper is to minimize the deviation from desirable situation through goal programming. The main function of the proposed model is formulated again along with new construction, auxiliary variables and optimum values. It consists of variables with the concept of “deviation of desirable situation”. In this paper, both of the deviations of desirable situations are shown by  and    which are undesired and should be minimized to achieve the optimum value. For this purpose, the fourth line of Tehran subway system and its intersectionssections are considered as the real world problem.

    Findings

    The model is solved by Lingo and optimum values are calculated. The model is developed based on goal programming and it can reduce the passenger waiting time and satisfaction which results in increased acceptance of public transportation in society. These findings are compared with current values of time tables for first and last movements. Findings indicated that the proposed model can reduce the passenger current waiting time by 42%.

     Research limitations/implications

    In this paper, the accurate amount of passenger population was determined in a day based on lines, separately. Also, it was difficult to collect study data from the Tehran subway system organization. The proposed approach resulted in reduced passenger waiting time. Suggestions for further study include examining and analyzing the factors causing train delay and comparing the results of each single line with another; using simulation method to develop an optimization model for time tabling of train movement in order to optimize energy consumption; calculating and optimizing the number of subway station staff; and optimizing models to design the subway station network.

    Practical implications

     As Tehran public transportation system is extending to cover more urban regions, the intersection stations will increase. Therefore, the role of these stations will be more tangible. Each intersection station scheduling affects the train movements in other stations and this continues throughout the length of the network. It means that each delay and pause will influence the other intersections, increasingly. The subway system managers can employ this model on other lines and reduce the waiting time of passengers in the whole Tehran subway.

     Social implications

    As mentioned earlier, the waiting time of passengers in different stations, especially in intersections, is an important factor in using subway system as an effective public transportation system. It will increase or decrease the rate of subway usage. More public transportation usage leads to less air pollution, less traffic and faster travels in the city, which are all desirable for society.

    Originality/value

    In this paper, a goal programming model was proposed to minimize the deviations in the objective function and subsequently, the passenger waiting time in intersection stations. As the intersection stations are increased, the role of the proposed method can be considered as a solution for public transportation in different cities of Iran.

    Keywords: Passengers waiting time, Intersection stations, Optimization models, Intersecting passengers
  • Mohsen Sheikh Sajadieh *, Mahsa Bahmani Tabrizi Pages 45-69
    Purpose

    Long-term interaction with supplies in supply chains has nowadays become a key activity in organizations, and the companies attempt to improve their capabilities by using it. Due to the limitations of capable suppliers, ongoing technological developments, and the market's new requirements, it is necessary to develop the shortlist of each organization's suppliers, which is both time-consuming and costly. Thus, the development of suppliers' competitive capabilities is a strategy for creating shared benefits for all members. But, what is the correct position of the suppliers' development? What is its preface?This research aims to design a model for the development of the suppliers of a contractual holding company within the domain of engineering and design, production, construction, erection, and commissioning to establish sustainability in the supply chain. Therefore, by creating a model, through giving prominence to appropriate relations with each supplier, the improvement of the suppliers through the combination of qualitative and decision support models will be provided, so that all quantitative and qualitative criteria of purchase management are taken into consideration.

     Design/methodology/approach

    In this research, a process model and software for suppliers' development in the contraction field is provided employing qualitative patterns and decision support models for the sustainability of the supply chain. For this, along with the growth factors, requirements of customers, and beneficiaries in environmental; social, and economic dimensions are included. Therefore, methods such as investment, performance enhancement of key purposes, and training are used. To evaluate the suggested model, ten suppliers, qualifying the requirements of the conglomerate contractual company, are recognized and analyzed for seven months in cognitive, development-monitoring, and executive sections. The results obtained confirm the validity of the model and software in expert panels.

    Findings

    The main findings of this research are the design of a comprehensive process model and software within a sustainable development framework. In the recent model, contrary to the previous research, all different working areas of the suppliers for all contractual companies with the various buyer and seller relations have been considered inclusively. The output of this model is the plan for the integrated development and improvement of each supplier.The tracking of the improvements gained for different areas shows that, out of 39.29 percent total improvement, 15.99 percent is related to 40 percent of the suppliers with strategic unity. The remaining 23.30 percent is related to other suppliers.

     Research limitations/implications

    The challenges are motivating suppliers' participation, the permission of client involvement into details, and delay of some development plans. For further research, it is suggested that the chapters of recognition instruments and the gap analysis be revised and, if necessary, the empty module of the model be completed. For the software section, the system can be developed integrally online.

     Practical implications

    Through reviewing suppliers, the development of suppliers was classified in the form of investment conglomerate company through consultation and training, persuasion, promotion of performance goals, the necessity to execute standards, and supervising their execution and legal obligations and determination of the strategies and key objectives. The other development tool was provided appropriate for any action suggested. The main barriers of improvement actions to be implemented by suppliers can be summarized as the lack of organization’s senior managers’ support due to the informal execution of the project within a short time (seven months), and more than one-year time needed for improvement actions (i.e., the results of the actions were not achieved in monitoring section).

     Social implications

    As the development and implementation of the model are related to the sustainable supply chain, the social responsibility in each supplier is also promoted through the assessment of the indicators. For this purpose, various methods including rules implementations, following national and international standards, training and investment are used.

     Originality/value

    The novelty of this research is the development and simultaneous implementation of the three phases (assessment, development, and monitoring) in an integrated sustainable supplier development model.

    Keywords: Supplier development, Supplier evaluation, Supply Chain Sustainability
  • Jafar Bagherinejad *, Mehdi Bashiri, Zahra Abedpour, Elnas Soltani Pages 71-87
    Purpose

    Hub location problems are getting more and more attention today due to their widespread application in designing product transportation systems and communication networks. In these systems, products (including data transmission, passenger transportation, freight forwarding and logistics, postal services, etc.) are shipped from multiple sources to multiple destinations. The performance of these systems can be improved by using hub points. In fact, instead of just deciding on a single period, a planning horizon with multiple time periods is considered. The necessity of doing this research is that decisions are made in each period according to the costs and flows of the same period. In the real world, facilities are usually depreciated after a certain period of time and must be closed or rebuilt if possible. 

    Design/methodology/approach

    In this research, hubs reconstruction is allowed, meaning it can be reconstructed to reduce costs rather than startups, to operate for a specified lifetime and to cover network demands. It is also selected to operate hubs from different contractors. In this study, there are also several levels of capacity to set up that can be selected with respect to the demand of the period, which is both sufficient and cheaper to meet the demands. Genetic algorithm has been used to solve and evaluate the model performance. In general, this study has attempted to provide comprehensive modeling for the multi-period hub location problem with multiple capacities. The investigated problem considered the hubs lifetime as well as the possibility of reconstruction at the end of lifetime. It has also been attempted to design the model to suit real-world conditions.  

    Findings

    Investigations in this study showed that the proposed model is more efficient than the previous models in terms of coordination and compliance with real-world conditions. Further,the validity of the proposed model was also evaluated by performing a variety of sensitivity analyzes. Solving the various numerical examples by the genetic algorithm and comparing them with the exact method demonstrates the acceptable performance of the meta heuristic method.  

    Research limitations/implications

    For future research and improvement of proposed model  the following recommendations  are suggested: Consider different capacity levels for nodes so that the capacity of each node can be changed at different times depending on the problems conditions. Assume that the hubs can be closed before the expiration date depending on the problems conditions. Consider case studies in various industries and model development with conditions much closer to real situations, for example in the field of urban transport, perishable products, emergency services, and so on. Using uncertain programming such as probabilistic and fuzzy programming to predict and plan the model and its parameters in successive periods. Providing solution methods with better performance and solving larger problems in rational times. For example, heuristic methods can reduce the complexity of the problem and thus solve larger samples in shorter times, so they will be useful.  

    Practical implications

    The main advantage of a multi-period problem over a single period problem is making the best decision in the time frame. In the single-period model, once the decision is made for all time periods, it is obvious that this decision will not be optimal because the parameters and conditions governing the problem are not the same over successive periods, so the result will not be global optimal. Another advantage is that the single-period model optimizes the cost of each period separately and it does not consider the relationship between the network structure of the nodes in different periods. Therefore, in this study, a multi-period model was proposed to obtain the global optimal solutions.  

    Originality/value

    The main difference between this study and previous work is the following: Providing a hub location model in which it is possible to select a contractor for each hub set up. In this research, the hubs have a known lifespan and this lifespan is determined after the contractor selection. Providing a new model that enables the choice between reconstructing and closing at the end of each hub's life by considering network costs.

    Keywords: Multiperiod Hub location problem, Dynamic demand, Multiple capacity, Hub lifecycle, Hub reconstructing, Genetic Algorithm
  • Karim Ebrahimi, Adel Azar *, Alireza Chitsazian Pages 89-109
    Purpose

    In today's world, cyberspace and, of course, the communication and information system in the web platform is among the most popular categories. This category has attracted the attention of various private and public sectors for various reasons, including increased productivity, increased transparency, and increased serviceability. Therefore, the purpose of this study is to improve the quality of services in the field of e-government and thus increase the efficiency of government.

     Design/methodology/approach

    The proposed model incorporates the key measures of e-government service quality to achieve better reliability and user satisfaction of e-government services while keeping the recurring expenditure low. This model has been designed by Interpretive Structural Modeling and DEMATEL. The researchers have architected and engineered key factors of e-government service quality and have developed an integrated model and identified the interactions among those factors. The case of this paper is the governmental kiosks as one of the main sites for delivering service.

    Findings

    This research resulted in a model that indicates e-government service quality measurement indicators including customer confidence, efficiency, customer relationship, first time service, variety of services, service availability, service traceability, service support, interoperability, infrastructure, compensation, fit, compliance, quality assurance, and complaint management. Thus in the first step, the criteria were identified; in the second step, the criteria were categorized and designed by the opinion of experts; and finally, the intensity of the relationship among the criteria was determined to be aware of influence and effectiveness among them.

     Research limitations/implications

    Design mechanisms to monitor advances in technology and e-government to improve the proposed model and update the model are the most important suggestions. Another suggestion is identifying the gap between the theoretical developed model and practice.

    Practical implications

    The implication of this study is to achieve improved quality and to reduce the cost from lack of knowledge of qualitative criteria, mapping key indicators within the framework of a scientific model to improve the quality of e-government services while missing key policymakers and practitioners. Implementing this model in practice can satisfy electronic service providers by applying a part of indicators such as efficiency, interoperability, and infrastructure and satisfy the receiver of services by another part of indicators such as quality assurance, first time service, and complaint management. As a result, if the model is fully implemented, it will satisfy both the service provider, and the customer.

    Social implications

     Reducing the gap between the people and the government and thus increasing public satisfaction is the most important achievement of this research. In addition, transparency, which is a very important issue, can be addressed in the context of the web. Thus, e-government can result in transparency and satisfaction.

    Originality/value

     Because no established mapping model for governmental kiosks has been provided for effective, low-cost, high-quality e-government service systems, the proposed mapping model closes this gap and provides guidelines to evaluate e-government services. The paper provides appropriate tools both to practitioners and policymakers who work with information and communication systems.

    Keywords: e-Government, services quality, Interpretive Structural Modeling (ISM), DEMATEL, Governmental kiosks, e-Service measurement
  • Asma Bakhtiari tavana *, Masood Rabieh, Mahdi Esmaeili Pages 111-132
    Purpose

    Suppliers, as one of the vital partners of the supply chain, contribute to creating a sustainable supply chain. Also, resilient supplier selection can help to reduce the severity of the disruptions' effects. Thus, the simultaneous application of the sustainability and resilience principles in the process of supplier selection and order allocation plays a significant role in achieving sustainability and continuity of business processes in the occurrence of disruptions. This study aims to select a set of sustainable and resilient suppliers and to allocate demand in an automotive supply chain under disruption risks.

    Design/methodology/approach

    In this research, a hybrid approach has been presented for evaluating and ranking suppliers based on sustainability criteria and modeling the problem of selecting a sustainable-resilient supplier and order allocation under disruption risks. VIKOR (Vlse Kriterijumska Optimizacija Kompromisno Resenje which means multi-criteria optimization and compromise solution, in Serbian) as a multi-criteria decision-making technique has been used to determine the sustainability score of suppliers and the results have been considered as the input parameter for the mathematical model. The proposed mathematical model is two-stage stochastic programming to minimize total cost and maximizing sustainability performance in the case of disruptions, which is solved using the Ɛ-constraint method. Multiple sourcing and flexibility in the production capacity of suppliers have been considered as effective strategies to reduce the severity of disruptions. Iran-Khodro supply chain data has been also used to validate the research model. Finally, sensitivity analysis has been performed to investigate the effects of parameters' change on the final results.

    Findings

    The results indicated that by increasing the importance coefficient of sustainability performance in the supply chain, the overall value of the supply process increases during disruptions, and multiple sourcing and the use of suppliers' flexible capacity are effective strategies in reducing the severity of disruptions. Also, examining the effect of reliability on the expected cost indicates that the occurrence probability of disruption risk in suppliers can affect the total cost of the procurement process and can also reduce the sustainability goals.

    Research limitations/implications

    In this research, the effect of disruption risk has been examined. As a subject of future study, the operational risk is suggested to be recognized in the supplier selection problem. Besides, unique events have been considered in the model of this research. In the future, semi-super and super events can be also studied. Finally, using other resilience strategies in supplier selection problem such as adopting backup suppliers, protecting suppliers, and pre-positioning inventory can be a potential direction for future research.

    Practical implications

    The company under study can consider the results of the presented model and focus on utilizing suppliers' flexible capacity, multiple sourcing instead of single sourcing of parts, partially. Given the importance of sustainable development, particularly in automotive supply chains, it is essential to consider the sustainability performance of suppliers in sourcing decisions with disruption risk in addition to cost and reliability criteria. Thus, the company can evaluate the suppliers' sustainable performance in the occurrence of disruption to achieve sustainable development and business continuity and to meet the needs of stakeholders.

    Social implications

    Due to the subject of this study, i.e. sustainable supplier selection in the resilient supply chain, the performance of each supplier has been evaluated based on social and environmental criteria to consider social responsibility and environmental issues in the sourcing decisions under disruption risk. Originality/value: A few studies have taken into account the dimensions of sustainability and supplier risk simultaneously in the field of supplier selection and demand allocation. Flexibility in the supply capacity of the supplier, as an effective resilience strategy, and economic criteria such as C/100 index, PPM production line, payday resistance, communication system, etc. have not been studied in the literature of sustainable and resilient supplier selection.

    Keywords: Supplier Selection, Order allocation, Sustainability, resilience, Disruption risk, stochastic programming