Fuzzy Critical Path Method Research Articles

Utilization of fuzzy critical path method and fuzzy program evaluation and review technique for building a hydroelectric power station

In this paper, fuzzy critical path method and fuzzy program evaluation and review technique are used to calculate the earliest project completion time for constructing a hydroelectric power plant project. Fuzzy trapezoidal numbers are used to estimate the activity time and determine the range of pessimistic to optimistic variation of time. Furthermore, the minimum and maximum times of project completion duration were calculated by using arithmetic operations and ranking of fuzzy trapezoidal numbers. These hybrid methods are able to deal with the limitations associated with classical critical path method and program evaluation and review technique. The fuzzy techniques were applied to network activities in a manner similar to the classical methods for optimizing the project completion duration, thereby minimizing the cost of the project. Analysis was carried out to determine the critical path through the use of fuzzy critical path method. The fuzzy program evaluation and review technique was also used to determine the probability of completing the project at a scheduled time. These two methods were then compared and the most probable scenarios were analyzed. Finally, it was concluded that fuzzy program evaluation and review technique is better than fuzzy critical path method and more efficient in terms of early project completion time.

Aircraft total turnaround time estimation using fuzzy critical path method

Airport Collaborative Decision Making (ACDM) flight scheduling plans rely on accurate predictions of both optimal and reliable aircraft turnaround times, which is one of the most difficult things to complete. In order to account for the effects of randomness and fuzziness on the turnaround process duration, this paper deals with transforming the probability distribution of well-fitted sub-processes into a cumulative density function, which is equivalent to the fuzzy membership function (FMF), and then using goodness-of-fit to determine the fuzzy membership grade of each turnaround sub-process. The turnaround time is calculated using the fuzzy critical path method (FCPM), which is a combination of the Critical Path Method (CPM) and fuzzy set theory. In order to verify this estimate, we created the FMF using historical data and compared it to turnaround times based on FCPM. A linear regression model is used to examine the relationship between arrival delays and the FCPM-based turnaround process. We also use historical data to generate fuzzy sets of different arrival delays using Frankfurt airport data from the summer of 2017 and conclude that delays are positively correlated with the FCPM-based turnaround process.

Regional development through energy infrastructure: A comparison and optimization of Iran-Pakistan-India (IPI) & Turkmenistan- Afghanistan-Pakistan-India (TAPI) gas pipelines

Pakistan is working on two pipeline projects, namely, Iran-Pakistan-India (IPI) and Turkmenistan-Afghanistan-Pakistan-India (TAPI) gas pipelines, to meet its energy supply-demand gap. This study's aims to compare these two projects and identify the most suitable option for Pakistan. Furthermore, as the TAPI project is progressing faster than the IPI project, this study also aims to identify the critical activities associated with TAPI projects. Finally, a model is proposed to optimize the material and transportation costs related to the TAPI project. The study's contribution by using fuzzy set theory-based multi-criteria decision-making (Fuzzy MCDM) to compare two projects along with usage of the Fuzzy Critical Path Method (FCPM) for the identification of critical activities associated with the TAPI project. Finally, the Genetic Algorithm is applied to optimize the material and transportation costs of the TAPI project. The results show that IPI has advantages over TAPI in terms of power generation, transportation cost, transits fee, and gas prices. The critical path analysis of the TAPI gas pipeline shows that it will take approximately 75 to 330.5 weeks to complete. The study is useful for the managers who have to work in these projects, the policymakers considering these projects at various levels, and the researcher having an interest in applying Fuzzy set theory with MCDM, CPM, and in the context of the energy infrastructure.

Application of intuitionistic fuzzy critical path method on airfreight ground operation systems

The main objective of this paper is to express how intuitionistic fuzzy critical path method helps and 11 improves the working process of the airfreight ground operation system. In this way, an example is discussed based 12 on the application of intuitionistic fuzzy critical path method for airfreight ground operation systems. Instead of 13 following the traditional method to find critical path and total completion duration of intuitionistic fuzzy critical 14 path analysis, we have proposed a new approach that is easier and simple to understand when compared with 15 existing methods. Here activity durations are represented as trapezoidal intuitionistic fuzzy numbers. Also, a 16 new centroid based ranking grade of modal value, left fuzziness and right fuzziness index of membership and 17 nonmembership functions of trapezoidal intuitionistic fuzzy numbers has been applied.

Application of intuitionistic fuzzy critical path method on airfreight ground operation systems

The main objective of this paper is to express how intuitionistic fuzzy critical path method helps and 11 improves the working process of the airfreight ground operation system. In this way, an example is discussed based 12 on the application of intuitionistic fuzzy critical path method for airfreight ground operation systems. Instead of 13 following the traditional method to find critical path and total completion duration of intuitionistic fuzzy critical 14 path analysis, we have proposed a new approach that is easier and simple to understand when compared with 15 existing methods. Here activity durations are represented as trapezoidal intuitionistic fuzzy numbers. Also, a 16 new centroid based ranking grade of modal value, left fuzziness and right fuzziness index of membership and 17 nonmembership functions of trapezoidal intuitionistic fuzzy numbers has been applied.

NOVEL BINARY OPERATIONS ON Z-NUMBERS AND THEIR APPLICATION IN FUZZY CRITICAL PATH METHOD

NOVEL BINARY OPERATIONS ON Z-NUMBERS AND THEIR APPLICATION IN FUZZY CRITICAL PATH METHOD

Fuzzy combinatorial optimization in four-dimensional tradeoff problem of cost-time-quality-risk in one dimension and in the second dimension of risk context in ambiguous mode

Purpose The optimization and tradeoff of cost-time-quality-risk in one dimension and this four-dimensional problem in ambiguous mode and risk can be neither predicted nor estimated. This study aims to solve this problem and rank fuzzy numbers using an innovative algorithm “STHD” and a special technique “radius of gyration” (ROG) for fuzzy answers, respectively. Design/methodology/approach First, it is the optimization of a fully fuzzy four-dimensional problem which has never been dealt with in regard to risk in ambiguous mode and complexities. Therefore, the risk is a parameter which has been examined neither in probability and estimableness mode nor in the ambiguous mode so far. Second, it is a fully fuzzy tradeoff which, based on the principle of incompatibility “Zadeh, 1973”, proposes that when the complexity of a system surpasses the limited point, it becomes impossible to define the performance of that system accurately, precisely and meaningfully. The authors believe that this principle is the source of fuzzy logic. Third, for calculating and ranking fuzzy numbers of answers, a special technique for fuzzy numbers has been used. Fourth, For the sake of ease, precision and efficiency, an innovative algorithm called the technique of hunting dolphins “STHD” has been used. Finally, the problem is very close to reality. By applying risk in ambiguous mode, the problem has been realistically looked at. Findings The results showed that the algorithm was highly robust, with its performance depending very little on the regulation of the parameters. Ranking fuzzy numbers using the ROG indicated the flexibility of fuzzy logic, and it was also determined that the most appropriate regulations were to ensure low time, risk and cost but maximum quality in calculations, which were produced non-uniformly based on the levels of Pareto answers. Originality/value The ROG and Chanas Fuzzy Critical Path Method as developed by other researchers have been used. Despite the increase in limitations, parameters can develop. The originality of this study with regard to evaluating the results of tradeoff combinatorial optimization is upon decision-making which has a special and highly strategic role in the fate of the project, with the research been conducted with a special approach and different tools in a fully fuzzy environment.

Fuzzy critical path method based on ranking methods using hexagonal fuzzy numbers for decision making

Fuzzy critical path method based on ranking methods using hexagonal fuzzy numbers for decision making

Presenting a Model Based on Fuzzy Application to Optimize the Time of IBS Projects in Gas Refineries

Nowadays, the construction industry has started to embrace IBS as a method of attaining better construction quality and productivity and reducing risks related to occupational safety and health. The built of pre-fabricated component in factories reduces many problems related to lack of purposing uncertainty in scheduling calculation and time management of projects. In the case of using IBS method for managing time in projects, former studies such as Allan Tay’s research, indicates that this method can save up at least 29% of overall completion period versus the conventional method. But beside mentioned advantages of this technical method, the projects could be optimized more and more in scheduling calculations. This issue is critical in gas refineries, since special parameters such as risk of spreading poison H 2 S gas and mandatory of performing projects in short time period events such as maintenance overhauls demands to perform projects in optimum time. Custom scheduling calculation of project planning uses the Critical Path Method (CPM) as a tool for Planning Project’s activities. The researches of this paper’s authors indicated that Fuzzy Critical Path Method (FCPM) is the best technique to manage the uncertainty in project scheduling and can save up the construction project’s time versus the custom methods. This paper aims to present a model based on fuzzy application in CPM calculations to optimize the time of Industrial Building System.

Critical Path with Various Distances of Type-2 Fuzzy Numbers

The critical path method (CPM) is a vital tool for planning and controlling complex projects. The successful implementation of CPM requires the availability of clear determined time duration for each activity. In practical situations this requirement is usually hard to fulfill, since many of these activities are uncertain, which leads to the development of fuzzy critical path method. In this paper, we propose a new approach to find critical path and its path length using some various distances of trapezoidal type-2 fuzzy numbers. An example is included to demonstrate our proposed approach.

English

English

Discussion with the paper 'Project costs planning in the conditions of uncertainty' by H. Štiková

In the paper, there is analysed one particular approach to the modelling uncertainty in the project management through an original version of the fuzzy CPM (Critical Path Method). First there is shown the relevance of using the fuzzy CPM in agriculture and the related branches and present the basics of the methods used. Then, there are described the imperfections of the work which is discussed and the impacts of the previously-published approach when applied in project management practice are emphasised. In the original paper, the author uses only the discrete fuzzy numbers for activity time durations which could be considered inappropriate for the time scheduling in project management. Consecutively, the direct application of the extension principle on the comparison of continuous durations could lead to the situation when both numbers can be greater than the second one with possibility equal to one. Moreover, the simple transformation of durations to the costs by linear equations with a positive slope does not respect the current project management theory and practice. Finally, the missing comparison of project fuzzy costs among individual variants of the project is calculated.  

Analysis of construction dynamic plan using fuzzy critical path method

Critical Path Method (CPM) technique has become widely recognized as valuable tool for the planning and scheduling large construction projects. The aim of this paper is to present an analytical method for finding the Critical Path in the precedence network diagram where the duration of each activity is represented by a trapezoidal fuzzy number. This Fuzzy Critical Path Method (FCPM) uses a defuzzification formula for trapezoidal fuzzy number and applies it on the total float (slack time) for each activity in the fuzzy precedence network to find the critical path. The method presented in this paper is very effective in determining the critical activities and finding the critical paths.

Fuzzy Critical Path Method Based on a New Approach of Ranking Fuzzy Numbers using Centroid of Centroids

The Critical Path Method (CPM) is useful for planning and control of complex projects. The CPM identifies the critical activities in the critical path of an activity network. The successful implementation of CPM requires the availability of clear determined time duration for each activity. However, in practical situations this requirement is usually hard to fulfil since many of activities will be executed for the first time. Hence, there is always uncertainty about the time durations of activities in the network planning. This has led to the development of fuzzy CPM. In this paper, a new approach of ranking fuzzy numbers using centroid of centroids of fuzzy numbers to its distance from original point is proposed. The proposed method can rank all types of fuzzy numbers including crisp numbers with different membership functions. The authors apply the proposed ranking method to develop a new fuzzy CPM. The proposed method is illustrated with an example.

Fuzzy Critical Path Method Based on Lexicographic Ordering

The Critical Path Method (CPM) is useful for planning and control of complex projects. The CPM identifies the critical activities in the critical path of an activity network. The successful implementation of CPM requires the availability of clear determined time duration for each activity. However, in practical situations this requirement is usually hard to fulfil since many of activities will be executed for the first time. Hence, there is always uncertainty about the time durations of activities in the network planning.  This has led to the development of fuzzy CPM.  In this paper, we use a Lexicographic ordering method for ranking fuzzy numbers to a critical path method in a fuzzy project network, where the duration time of each activity is represented by a trapezoidal fuzzy number. The proposed method is compared with fuzzy CPM based on different ranking methods of fuzzy numbers. The comparison reveals that the method proposed in this paper is more effective in determining the activity criticalities and finding the critical path.   This new method is simple in calculating fuzzy critical path than many methods proposed so far in literature.  

APPLICATION OF FUZZY CRITICAL PATH METHOD TO AIRPORTS CARGO GROUND OPERATION SYSTEMS

To cut down cost in a competitive environment, airlines must avoid delays and operation inefficiencies in both airside and landside. However, previous studies have paid little attention to an airlines’ ground operation in airports’ cargo terminals. The purpose of this paper is to demonstrate how to employ the Fuzzy Critical Path method (CPM) to find out airport’s ground critical operation processes and improve. The result of this study suggests redesigning airports’ cargo handling processes can improve airlines’ freight service performance in terms of freight handling speed, cargo service quality, and freight handling cost in hub airports.

Fuzzy Critical Path Method Based on Signed-Distance Ranking and Statistical Confidence-Interval Estimates

Activity networks have proved very useful for certain types of project performance evaluations. The purpose of the critical path method (CPM) is to identify the critical activities in the critical path of an activity network. However, the unknowns or vagueness about the time duration for activities in network planning, has led to the development of fuzzy CPM. In this paper, we propose an approach that combines fuzzy mathematics with statistics to solve practical problems in unknown or vague situations. We introduce a fuzzy CPM based on statistical confidence-interval estimates and a signed-distance ranking for (1−α) fuzzy number levels. We not only derive the level (1−α) of fuzzy numbers from (1−α)×100% statistical data confidence-interval estimates, but also use the signed-distance ranking method to define the ordering. The primary result obtained from this study, is a theorem through which the critical path in the fuzzy sense is obtained based on statistical confidence-interval estimates.

Corrections to "Fuzzy critical path method based on signed distance ranking of fuzzy numbers"

Corrections to "Fuzzy critical path method based on signed distance ranking of fuzzy numbers"

Fuzzy critical path method based on signed distance ranking of fuzzy numbers

We apply a signed distance ranking method for fuzzy numbers to a critical path method for activity-on-edge (AOE) networks. We use signed distance ranking to define ordering simply, which means we can use both positive and negative values to define ordering. The primary result obtained in the paper is the use of signed distance ranking of fuzzy numbers obtaining Properties 3 and 4. We conclude that the fuzzy AOE network is an extension of the crisp AOE network, and thus the fuzzy critical path in a fuzzy AOE network, under some conditions, is the same as the crisp critical path in a crisp AOE network.

Fuzzy critical path method

There have been several attempts in the literature to apply fuzzy numbers to the critical path method. The result delivers the earliest expected time for each event of the project. This paper shows that further extension can be made by considering the interactive fuzzy subtraction and by observing that only the nonnegative part of the fuzzy numbers can have physical interpretation. Based on these two observations, the formulas for the latest allowable time and slack for each event are presented. The availability of fuzzy slacks provides enough information, at least for certain /spl alpha/-level of the slack, to identify the critical path in the network model of the project. Thus, practically we can generalize the critical path method by accepting imprecise, fuzzy data for the duration of the activities.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>