GERT Network Research Articles

Assessing the collaborative quality value in nuclear power intelligent construction: A value chain analysis method based on double-layer GERT network

Due to the large number of participants and the multi-dimensional heterogeneity of economic activities, the value creation links are hidden and the value relationship is difficult to identify. Only paying attention to the effect and cost input of a single enterprise’s quality business cannot maximize the value of collaborative quality control, and cannot meet the requirements of nuclear power intelligent construction. Therefore, we propose to use collaborative quality value to characterize the value creation process and coordinate the interest relationship and value distribution among participants. On this basis, a collaborative quality value chain analysis method based on the double-layer GERT network is studied to quantitatively calculate the collaborative quality value. Specifically, the collaborative quality assurance mode is constructed and the interaction behavior among participants is analyzed. The value transfer and enhancement across participants is represented by the double-layer GERT network model, and the global and local values of the value chain are quantitatively measured based on the equivalent transfer function. Then, the key quality assurance business and activities that restrict the whole chain value-added are explored, and the collaborative quality value-added strategies are proposed. Finally, the effectiveness of this method is verified by a case study involving the fabrication of reactor pressure vessel (RPV) support inside a nuclear power project. This study provides a new method for realizing the value evaluation of collaborative quality control and maximizing the collaborative quality value of the whole value chain.

Process management of heterogeneous services in a digital university based on modified GERT networks

The research is devoted to the issues of managing the processes of the information and computing environment in a digital university, which have a distributed, heterogeneous, probabilistic, poorly controlled nature. To improve the efficiency of managing the processes in a digital university, the authors of the research analyzed scientific papers in the field of the information technology infrastructure of organizational and economic systems and universities, formulated the basic principles of information technology infrastructure in a digital university within the conceptual framework of innovative infrastructure for modern organizations, developed a generalized scheme of IT services in a digital university, and elaborated a mathematical apparatus of modified GERT networks to control the processes of heterogeneous services in a digital university. The practical value of the research results is related to the development of new approaches to information management and processes of a modern organization based on the principles of consistency, complexity, and compliance with an appropriate balance between the distribution and integration of data flows. These developments can be replicated with certain modifications to a wide range of organizational and economic systems that are in the stage of digital transformation.

Reliability analysis on energy storage system combining GO-FLOW methodology with GERT network

Energy storage systems are widely used in various industrial areas, playing a crucial role in improving system reliability. In the energy storage system, the batteries serve as standbys for generators and have an auxiliary regulation function, so the complex relationship between them is unable to be accurately described by the basic GO-FLOW operators. To address this issue, this paper proposes a new operator for simulating the energy storage system, employing the GERT network for modelling and calculation. In this approach, the energy storage system operator is created to represent the energy storage system with ‘n generators with l degradation states, m batteries’. Firstly, each degradation state of generators is determined. Secondly, each macro state of the energy storage system is determined by combining the states of the batteries. Finally, based on the relationships between these states, the steady-state availability of the energy storage system is obtained using the GERT algorithm. A numerical example of a repairable power supply system is employed to validate the feasibility and effectiveness of the model and algorithm. And this method holds great significance for the reliability analysis of multi-state complex systems.

Digitalization of the organizational structure of an agro-industrial enterprise based on the GERT-network computational model

The article discusses an approach to digitizing the organizational structure of an agro-industrial enterprise based on the GERT network model. The transformation of the business process of coordinating primary procurement needs into a GERT network is shown. The possibility of transforming the GERT network for performers of functions is identified to further optimize the organizational structure of the business process in agro-industrial enterprises. The results of calculating the obtained GERT network taking into account the features of the business process are presented. The proposed equivalent transformations of the GERT network provide the possibility of fast digital modelling and, therefore, enable efficient reorganization of the enterprise's organizational structure.

Analysis of the Factors Influencing the Vulnerability of the GERT Network for the Quality Chain Based on Visual Boundary Positioning for Service-Oriented Manufacturing Systems

Analysis of the Factors Influencing the Vulnerability of the GERT Network for the Quality Chain Based on Visual Boundary Positioning for Service-Oriented Manufacturing Systems

Computational approach to the structure spectral analysis of GERT-network models of mobile object monitoring systems

The paper considers the application of the computational approach to the structure spectral analysis of GERT-network models of mobile object monitoring systems. The structure of the system for monitoring mobile objects using satellite communication channels is presented, in particular, the structure of the system for monitoring the flight path of aircraft. It is shown that the structure of monitoring systems can be represented as a GERT-network model, which allows at the initial stage to consider various options for the formation of interaction between a mobile object, for example, a manned or unmanned aerial vehicle, and a ground control complex. The main idea of the approach is to transform a known graph into a graph with the desired spectrum, which corresponds to a valid implementation of the GERT network graph. Obviously, the set of admissible implementations also includes a graph with the maximum probability of completing the process in a given time. The results are presented, which allow, when analyzing the GERT-network structure of a monitoring system, to assess, by fairly simple methods, the compliance of a structure variant with a number of requirements that apply to the system as a whole.

Development of a fuzzy GERT-model for investigating common software vulnerabilities

This paper has determined the relevance of the issue related to improving the accuracy of the results of mathematical modeling of the software security testing process. The fuzzy GERT-modeling methods have been analyzed. The necessity and possibility of improving the accuracy of the results of mathematical formalization of the process of studying software vulnerabilities under the conditions of fuzziness of input and intermediate data have been determined. To this end, based on the mathematical apparatus of fuzzy network modeling, a fuzzy GERT model has been built for investigating software vulnerabilities. A distinctive feature of this model is to take into consideration the probabilistic characteristics of transitions from state to state along with time characteristics. As part of the simulation, the following stages of the study were performed. To schematically describe the procedures for studying software vulnerabilities, a structural model of this process has been constructed. A "reference GERT model" has been developed for investigating software vulnerabilities. The process was described in the form of a standard GERT network. The algorithm of equivalent transformations of the GERT network has been improved, which differs from known ones by considering the capabilities of the extended range of typical structures of parallel branches between neighboring nodes. Analytical expressions are presented to calculate the average time spent in the branches and the probability of successful completion of studies in each node. The calculation of these probabilistic-temporal characteristics has been carried out in accordance with data on the simplified equivalent fuzzy GERT network for the process of investigating software vulnerabilities. Comparative studies were conducted to confirm the accuracy and reliability of the results obtained. The results of the experiment showed that in comparison with the reference model, the fuzziness of the input characteristic of the time of conducting studies of software vulnerabilities was reduced, which made it possible to improve the accuracy of the simulation results.

ADC-GERT network parameter estimation model for mission effectiveness of joint operation system

Effectiveness evaluation of the joint operation system is an important basis for the demonstration and development of weapon equipment. With the consideration that existing models of system effectiveness evaluation seldom describe the structural relationship among equipment clearly as well as reflect the dynamic, the analog-to-digital converter-graphical evaluation and review technique (ADC-GERT) network parameter estimation model is proposed based on the ADC model and the joint operation system structure. Firstly, analysis of the joint operation system structure and operation process is conducted to build the GERT network, where equipment subsystems are nodes and activities are directed arches. Then the mission effectiveness of equipment subsystems is calculated by the ADC model. The probability transfer parameters are modified by the mission effectiveness of equipment subsystems based on the Bayesian theorem, with the ADC-GERT network parameter estimation model constructed. Finally, a case study is used to validate the efficiency and dynamic of the ADC-GERT network parameter estimation model.

The concept of digitization and research in the field of gert networks management of public sector projects and programs

The modern world space has long gone beyond the construction of the information society, because digital technologies are absorbing more and more spheres of public life, radically changing the forms and methods of their implementation. Therefore, most countries in the world focus on development in the direction of building a "digital economy", using all possible competitive advantages from its implementation. Ukraine is trying to keep up with the development of information technology in various areas of both public sector governance and public life. Some achievements have been made, but the systemic and synergistic effect on the country's development has not been achieved, despite the significant potential of domestic IT specialists, who are among the top five IT outsourcers in the world. In my opinion, the use of digitalization in the field of governance in the public sector can be a significant impetus for digital transformation for the development of Ukraine's competitive economy. Therefore, we need an analysis of theoretical and practical approaches to a detailed study of the features of digitalization in the public sector of Ukraine during its digital transformation and the development of proposals for their implementation, which became the topic of my research.

Graph Evaluation and Review Technique for Emergency Logistics Distribution in Complex Environment

Emergency logistics is one of the important measures to solve the unconventional sudden disaster. The research on the distribution design of emergency logistics project has an important supporting role for the whole emergency rescue system. Therefore, it is necessary to analyze and plan the emergency logistics project scientifically in order to better serve the emergency rescue system. In view of the defect that the current emergency logistics model cannot completely describe the whole emergency logistics process, this paper proposes a new emergency logistics distribution model by using GERT random network. From the perspective of system, this model fully considers the possible situation in the process of emergency material transportation and puts forward the corresponding countermeasures, so as to improve the transportation efficiency of rescue materials in the actual disaster relief activities to speed up disaster relief. Based on the properties of moment generating function and the calculation method of Mason formula, this paper fully considers the success probability, risk probability, delivery time, and other factors of the distribution route and puts forward the transshipment scheme of each logistics site to the disaster sites. After that, the effectiveness of GERT stochastic network in the process of emergency distribution is verified by an example of a logistics distribution route, which provides decision-making basis for relevant departments. Compared with the literature, this paper uses GERT network model to intuitively and clearly express the overall process of emergency material distribution, breaks through the thinking mode of simply choosing the distribution path in the distribution process, combines with the dynamic changes of the distribution environment, and comprehensively considers the timeliness and traffic capacity of emergency material distribution in sudden disasters, so as to provide reference for emergency management in complex and random situations for decision-making reference.

Development of protecting a software product mathematical model from unlicensed copying based on the GERT method

The subject of the research is methods and algorithms for developing the GERT networks that provide a hidden transition along the branches of the control logic graph and the ability to encode digital watermarks in the context of existing threats to the licensing security of software systems. The aim of the work is to develop a system of a software product licensed security based on hidden transition algorithms in GERT networks that carry the properties of digital watermarks. The article solves the following goal: development of a model of a software licensed security system based on the developed algorithms using GERT networks. Methods of mathematical modeling, numerical experiment, complexity theory and cryptography are used. The following results were obtained: on the basis of the analysis of existing models for ensuring software licensed security, the main requirements for the algorithms synthesized within the framework of the developed model, as well as for the machine implementation of the algorithm, were identified. Based on the investigation of existing watermark systems, methods of attack on them, as well as the requirements put forward for the developed model, a licensing security algorithm was formed based on the watermark system. Conclusions: for the first time, algorithms for safe transition in GERT-networks were developed, which are used as a graph of the control logic of a software product. This logic is implemented depending on the identification or serial number; a model of a licensed security system has been developed, which has not only empirical, but also theoretical substantiation of resistance to attacks by an intruder.

Research on Knowledge Transfer Effect of Innovation Cluster of High-tech Industry Based on GERT Network

The GERT network model based on the knowledge transfer process of high-tech industrial innovation cluster is constructed, and the knowledge transfer measurement coefficient is put forward, and the influence parameters are introduced to analyze the influence of parameters on the knowledge transfer measurement coefficient Furthermore, combined with examples and using numerical simulation, this paper explores the changing characteristics of knowledge transfer performance of high-tech industrial innovation clusters. The results show that enhancing R&D incentives and enterprises' absorptive capacity can improve the knowledge transfer performance in the process of knowledge transfer in high-tech industrial innovation clusters. The coefficient of knowledge transfer measure has a threshold value, and when it reaches the threshold value, the incentive and absorption ability is the best. The research conclusions can provide decision-making reference for improving the knowledge transfer performance of high-tech industrial innovation clusters.

Research on D-GERT Model of Joint Operational Situation Assessment Based on Information Flow

To solve the problem of inaccurate description of battlefield information changes in the process of joint system operations, this paper constructed a joint operational situation assessment D-GERT network model based on information flow, on the basis of the GERT network. And the calculation method of the threat degree, the increment of battlefield information value and the importance of network nodes were given. Finally, MATLAB was used to simulate and verify the model. The results showed that the method in this paper conforms to objective reality and can provide good method support for the commander's combat decision-making.

Stochastic model of project implementation of the new generation ecological materials – sulfur polymers in key branches of the economy

In the article, the authors propose a stochastic model for the implementation of the project for the introduction of sulfur polymers in key sectors of the Ukrainian economy. A model based on GERT networks and the theory of closed flow graphs allow you to clearly and fully represent the stages, take into account the stochastic nature of both the development process itself (through the use of probabilistic considerations regarding the time of each operation and the reliability of its execution), and the influence of various factors of endo- and exogenous in nature. The project provides for the development and application of ecological polymer composite materials (sulfur asphalt concrete and sulfur concrete) with the introduction of industrial waste, including sulfur-containing ones, to ensure the principles of a circular economy. According to the authors, the project is one of the conditions for stimulating the implementation of strategic directions for the development of the domestic industry on the use of the latest environmental technologies of sulfur polymer materials in the construction of the country’s infrastructure, providing for a reduction in the ecological, carbon, sulfur-containing and material footprint, the transition to environmentally friendly technological solutions, the introduction of principles of circularity of the economy.

REAVILING THE DISTRIBUTION REGULARITIES OF THE PROCEDURE EXECUTION TIME OF THE ALGORITHM OF TOWER CONTROLLER`S ACTIONS USING GERT NETWORKS

The article discusses issues related to the calculation of the parameters distribution of the procedure execution time of the algorithm of the Tower controller`s actions when servicing the aircraft performing the approach (hereinafter simply the ALGORITHM), using the Graphical Evaluation and Review Technique (GERT network). ALGORITHM is an integral part of the trainee reference (or model-following) model in the intelligent training system ATC of Tower, which is being developed by the Department of the Information Technologies of the Flight Academy of the National Aviation University. The reference model is formed on the basis of a list (set) of extremely detailed technological operations, the order of performing these operations upon a specific situation, a model of information flows circulation at the specialist's workplace, reference values, and time spent probabilistic models on performing technological operations. The reference model in the process of system functioning closely interacts with the trainee current model, thereby ensuring the fixation of his mistakes. On the basis of his mistakes, the intelligent system forms an individual training trajectory for the trainee and provides an opportunity for an objective automatic assessment of his operation activities. The use of the GERT network in calculating the ALGORITHM time distribution parameters allows obtaining the expected mean time value and the root-mean-square (standard) deviation, but in some cases, it does not allow calculating the execution time of its individual parts, for which the time is directly proportional to the performance characteristics of an aircraft.

РЕАЛИЗАЦИЯ ЦИФРОВОГО ДВОЙНИКА БИЗНЕС-ПРОЦЕССОВ НА БАЗЕ СИ-СТЕМЫ ELMA

This paper describes a prototype of a digital twin of a business process model. The apparatus of GERT networks are used to predict the parameters. BPMS ELMA was used as a technical platform. The structure and parameters of the GERT model are continuously updated based on the ELMA database.

The digital twin of the business process model

In this paper, we propose a solution to the problem of organizational management based on high-precision simulation models designed for numerical forecasting of the parameters of business process models - duration, labor intensity and resource intensity, cost. The solution is implemented as a prototype twin of the business process system model. To solve the problem of predicting the numerical indicators of a business process model, the formula and algorithmic apparatus of stochastic GERT networks is used. BPMS ELMA was used as a technical platform for the implementation of a digital twin prototype. To solve this problem, the apparatus of stochastic GERT networks is used. An edge of the GERT network is associated with the operation of the business process, and the node of the GERT network with an event or gateway of the business process. An algorithm for translating a model of a business process into an equivalent GERT network, as well as calculating the parameters of the law of distribution of the cost of a business process based on the obtained GERT network, is given. The proposed tool, implemented in the digital twin modeling module, allows solving the problems of predicting the dynamics of discrete-event models described in BPMN notation without using statistical simulation models. Continuous updating of the structure of the GERT-model in accordance with the modification of the process in the ELMA system and clarification of the parameters of probabilities, the type of distribution laws and their parameters based on the accumulated data of the digital shadow of the business process allows us to talk about the implementation of a high-precision forecasting model of the business process in the proposed digital twin model.

Building a GERT model of life cycle of educational and scientific information resources using Process Mining technology

The main priority of this article is to develop a tool for numerical forecasting of the life cycle of information resources based on actual life cycle data in the form of event logs of the resource history. To solve this problem, we used the GERT network device. To build a GERT network describes the life cycle model of an information resource, we were used methods of intellectual analysis of processes (Process Mining) implemented with the ProM Framework. In the course of the work, an analysis of the life cycle of information resources of the Scientific electronic online library was carried out. The work considers the process of extracting data used for modeling the GERT network, as well as the process of identifying the law of distribution of the probability density of the duration of the life cycle stages. The model of the GERT network is constructed and the law of distribution of the probability density of the duration of the life cycle of an information resource was described. The obtained result confirms the applicability of Process Mining technology to probabilistic analysis and forecasting of the life cycle of information resources.

Подход к построению прогностической модели жизненного цикла информационных ресурсов на базе стохастических gert-сетей и технологии processmining

The article proposes an approach to predicting the numerical parameters of the life cycle of information resources. The main task of this work is to develop a tool for numerical forecasting of the life cycle of information resources based on actual life cycle data in the form of resource history event logs. The forecast is carried out using the apparatus of stochastic GERT networks. The construction of the GERT model is performed using the Process Mining algorithmic apparatus and the ProM software framework. The object of the analysis was the data of the Scientific Electronic Library Online. The data is publicly available on the Kaggle.com website. To build a GERT network describing the life cycle model of an information resource, we used the methods of intellectual analysis of Process Mining processes implemented using the ProM Framework. In the course of the work, an analysis of the life cycle of information resources of the Scientific Electronic Online Library was carried out. The paper presents the process of extracting data used to model a GERT network using the ProM framework. The data obtained made it possible to restore the topology of the stochastic network and identify the laws of probability density distribution of the duration of the life cycle stages. On the basis of the constructed GERT-network, the law of distribution of the probability density of the duration of the life cycle of an information resource was described. The obtained result confirms the applicability of Process Mining technology to probabilistic analysis and forecasting of the life cycle of information resources.

Numerical modelling of the process of implementing media educational projects using GERT networks

The purpose of this work was to test the applicability of the methods for work networks based on the stochastic GERT networks analysing to the analysis and forecasting of the executing similar projects processes. The experimental object was the data on the implementation of media education projects by students of the general education lyceum. The processes were modelled using the graphical BPMN methodology. For numerical prediction, we used formulas and algorithms for constructing and analysing stochastic GERT networks. The GERT network, built on the basis of data analysis of the implemented media educational projects, made it possible to calculate the probability distribution density of the time of the media project execution, as well as to calculate the first central moments of the distribution law-significant in practice indicators of the average execution time of a media project, taking into account loops and cycles, as well as an indicator of the variance of the project execution time, which makes it possible to estimate the spread of the execution time of the same type of media projects. The result obtained allows us to speak about the applicability of the GERT-model for predicting the numerical indicators of models of business processes for executing projects of the same type as an alternative to statistical simulation.