Project management plays an important role in the discussion of risk control. In fact, its history goes back to the early years of the 1900s, that is, when Henry Gantt, with the development of his innovative bar chart, initiated the next movement during the 1950s to 1960s in American military and aerospace projects and then He went to England, but his fame has been due to several factors, including the use of Gantt charts, his collaboration with Taylor in the scientific theory of management, and his fame in the study of naval ship building management, of course, he was a pioneer in allocating resources. This caused the 1950s to 1960s to be recognized as the early years of project management growth and development in the contemporary arena and the beginning of the formation and development of many methods and knowledge related to the management of the ten principles of project management and this made them famous in management [1]. The written report of the Social Security Organization (SSO) indicates that among various industries, the construction industry has the most accidents caused by work, so that in addition to the increase, it also has a very high intensity, and also because many people are working in this vast industry. Therefore, it requires special attention. In 2013, the highest number of accidents caused by the work of insured persons who were affected by occupational accidents in the field of economic activity is related to structural works with a figure equal to 5479 (26.69%) accidents. Also, the events caused by work, in addition to causing financial losses to the society, lead to the imposition of many human losses on the society [2]. Nowadays, the major part of the capital of every country, especially the developing countries, is dedicated to construction projects and its infrastructure, and one of the factors of economic growth and development of any society is the success in the implementation of its construction projects. Construction and oil projects are complex works and are inevitably described with a set of drawings and technical specifications. Project management is one of the special tools for the success of complex activities such as projects [3]. Since project planning and control includes various aspects such as goal setting, risk management, management procedures and change management, it has a significant effect on the success of construction projects. Basically, things like the occurrence of faults, land acquisition and landslides are among the risks of oil construction projects, which if not investigated, will reduce the quality of the project, increase the execution time and even cause irreparable damage, so these risks should be evaluated at the beginning of the work. and reviewed and experts' opinions should be used [4]. Fuzzification is a method in which verbal expressions and qualitative values are quantified with fuzzy numbers, so the first step in solving a problem based on rationalization in management is to make the data fuzzy. When you use the experts' point of view to compare criteria or estimate their values, they express their point of view in verbal expressions. The traditional process of quantifying people's views cannot fully reflect the human thinking style. In other words, the use of fuzzy sets is more compatible with human linguistic and sometimes ambiguous explanations. Therefore, it is better to make long-term predictions and make decisions in the real world by using fuzzy sets (using fuzzy numbers). For the first time in 1965 AD, an Iranian-born scientist and professor at Berkeley University with the title of Professor Lotfali Asgarzadeh proposed this logic. This logic is against Aristotle's two-valued logic, which said that the answer to all questions in the world is yes or no, but in fact, fuzzy logic introduces the world as it is and is more similar to human nature. Despite the many benefits of this logic, its main problem is that it cannot be a producer of human patterns because human thought patterns are often intuitive and mathematics cannot understand them and we hope that we should let overcome most of the negative results of the risks [5]. In general, major developments in the business environment have increased competition and management difficulty in organizations, so organizations need risk-taking and capable managers to adopt these inherent complexities when making important decisions. In production business environments, industries active in the food, pharmaceutical and petroleum sectors have higher risks and higher coefficients, therefore, the implementation of risk management techniques in these companies is of great importance [6]. It should be taken into account that today it is clear that the most common cause od accidents in the construction and oil industries is the variability of human performance, which is different from the traditional human error paradigm and used more modern in order to improve the progress of the project, also the discussion of administrative bureaucracy is also effective in this matter [7]. In this project, first 30 residual important risks were identified in five different departments with meetings held with experts, and according to the effects of 28 effective criteria on them, they were ranked with the help of two Fuzzy and matrix risk methods.

Wang and Wang [8], on an article entitled the assessment of the risks of passing through substructures the existing under the tunnels worked with the help of Fuzzy method and cloud model. They believed to that in addition to the risks in while working in construction projects, some risks are also related to passing through infrastructures such as tunnels and it stays in place due to the fuzzy and randomness of the construction environment, the use of simulation methods such as Monte Carlo while produce highly fluctuating and non-uniform results that are not reliable. They with the help of analysis and analyzing previous experiences, he designed a cloud model algorithm with the help of fuzzy method and tested it in a real example and finally, the effectiveness of this model was confirmed. The final results of this research showed that calculations the cloud model is much easier than other methods and reflects the relationship between indicators and results to determine the level, there are risks and also, the accuracy of these models is very high and there is no significant difference with the main results. Other researchers also, in the future, by defining more improved methods, they can develop and strengthen the fuzzy method at global levels and be used in construction projects [8].

Daniali et al. [9], on an article titled identifying and evaluating project management risks with using gray Shannon’s entropy and FMEA techniques worked, they first held many meetings with experts and Yazd civil engineering specialists have identified 30 effective risks for the management of construction projects of Yazd Municipality and then by designing the questionnaire and with the help of gray numbers, the weight of the risk factors. The diagnosis was obtained from the qualitative mode in the form of a numerical interval. Then 5 experts were used and with the help of the FMEA method. The decision matrix was formed and the weights were obtained with the help of normalization and gray entropy technique [9].

Ndaw et al. [10] worked on an article entitled “reviewing residual risks in Senegal banks”. They stated that risk is a potential danger that arises from some current processes or future events. Banks take many security measures to secure safe transactions but fraud in ATM and POSE machines has increased significantly so in order to keep customers satisfied, banks should inform their customers about new protocols. African banks made regional and safe development the main focus of their work but due to lack of information, they are not allowed to assess all risks so they have to do it manually. In this research first a proposed quantitative security model that shows the impact of the risk of banking information systems in case of using FMECA is presented, which includes three stages of maturity control, types of control and criteria detection. This model was designed during meetings with the managers of Senegal’s banks. The causes and effects of failures were identified and to test the validity of the work, the values obtained in the model were compared with the values of the evaluators during the work sessions and the results was satisfactory [10].

Baradaran [2] worked on an article titled “evaluation and prioritization of urban rail transport risks with the Gray Hierarchical Analysis Process (GAHP)”. First, by reviewing the existing literature, the issues faced by the passengers and employees of the metro were identified. Then for a deeper investigation, by holding meetings with railway transportation engineers of Yazd municipality, 13 risks were identified with the help of 9 criteria and sub-criteria. Then with the help of gray numbers or interval in AHP, the Likert scale was performed and the matrix of paired comparisons was obtained and a non-linear and linear optimization model was used to calculate the local and global weights and the risks were finally ranked and the rations were compared. The results showed that closing the train door, conflict between passengers and getting injured while using the escalator are important risks [2].

Rahnamai et. al [3], on research titled evaluating companies’ risk management using discussed the application of gray Multi Criteria Decision Making (MCDM) with entropy weight and believed that the major developments in the business environment and work have increased competition and made management difficult in organizations. They are fisted to measure management tools companies’ risk, four criteria C1, C2, C3 and C4 based on the Kosovio medel for managing strategic risks, risk they defined operational risks, reporting risks and risks of non-compliance with laws and regulations. This type of research applied and with the aim of collecting data and informational 20 Tehran Stock exchange companies during the years 2012- 2017 and then with the help of these 4 criteria, the normalized weight matrix and formed and the degree of gray relation of the matrix was obtained one by one and with the help of weighted entropy method and gray analysis method, this information was put in MATLAB software and a multi-criteria decision model was used for the final ranking of companies and the results showed that this ranking it has caused recognition of the position of these listed companies in relation to the optimal points and they tried to develop strategic plans reduce this distance and revise it [3].

In this research, an oil construction project in Iran was discussed, which includes 80 employees of the employer and 70 employees of the contractor. The remaining risks in the two parts of design and implementation were investigated in five parts: mechanical, electrical, civil, instruments and financial. 28 criteria affecting these risks along with the risks themselves were identified by holding meetings with project supervisors and experts. It should be mentioned that this project has completed 70% of its planned progress. This project includes 7 pumping stations, a number of pumps and 5 pressure breakers. This project has faced many financial problems, including lack of funds and lack of timely allocation of funds, which has caused stops along the way of the project. Also, issues such as sudden changes in maps and soil mechanics are among the other issues that have had an impact on the progress of different parts of the project. In Table 2, the criteria studied in this project, some of which have been obtained from studies of previous similar projects, are listed.

This project is very importance and changes have been made many times in the field od designing its maps in order to move forward in the best possible way and get the best output and have the lowest cost.

In the next stage, from each department that was mentioned, 5 people including the head of that department were selected to answer the two questionnaires, but a total of 15 people agreed to answer the questions orally and the others due to many works, they were busy and couldn't help.

In the Table 3, the details of the respondents are given along with their educational qualifications and work experience.

Step 1. In this step we convert qualitative expressions to triangular fuzzy expressions with the help of Table 1 and we repeat each relevant weight three times because its important and that a triangular fuzzy number consist of three components.

Step 2. The matrix obtained from the previous step is descaled with the help of the fuzzy method and Eq. (4).

Step 3. In the Step 3, the weighted normalized matrix is obtained from the product of the normalized matrix and the weights.

Step 4. In the next step of Fuzzy SAW, the row summation of the weighted normalized matrix is done in such a way that the beginning, middle and end regions are added together separately.

Step 5. At this stage, the obtained results are defuzzied by the center of gravity method by Eq. (6). It should be noted that this step is very important.

Step 6. In the last step, the numbers obtained from the previous step are ranked in descending order to identified the most important and critical risks. Then the most critical residual important risks are determined by priority of risk level. In Table 4, the final ranking results can be seen.

It should be mentioned that to solve the initial fuzzy SAW method, the weights come with the help of an arbitrary method such as entropy to be used in the calculations. It should be noted that the sum of the weights is equal to one. All these items are listed in Table 5.

Also, to convert the verbal expressions of the 5-point Likert spectrum into triangular fuzzy, the Table 6 was used as described below. Basically, the Likert scale is one of the methods that can help a lot to convert verbal expressions into numerical values.

This Likert scale includes the numbers 1 meaning very low, number 3 means low, number 5 means average, number 7 means high and number 9 means very high and the questionnaire in this research is oral and in the form of survey studies.

The ranking of remaining and important risks by two fuzzy methods have differences, which shows the difference in the nature of these two methods.

The ranking of the remaining risks by the risk matrix method, which was obtained using the information of questionnaire number one, has differences with other methods, the reasons of which can be attributed to the difference in the framework and shape of these methods.

According to the opinions of specialists, supervisors and experts and the analysis of their answers, it was found that the factors that caused the project to slow down and to some extent stop in the time frames, such as the lack of timely budget injection, insufficient budget injection in order to Renovation and repairs of equipment, exchange rate fluctuations and international sanctions have caused the disconnection of relations with related countries and companies.

The use of a small study sample in this research is one of the things that had an impact on the results, which of course was the limited number of people who were familiar with risk.

The authors declare no conflict of interest.

All data are included in the text.

This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors.