Miklós Hajdu - Academia.edu (original) (raw)
Papers by Miklós Hajdu
Proceedings of the Creative Construction Conference 2023
The importance of quality is now recognized in every expertise. Quality management has significan... more The importance of quality is now recognized in every expertise. Quality management has significantly evolved over more than the last half-century, and the methods and techniques involved have been developed, their levels described in detail. During this evolutionary process, quality has been defined in several quality management sources, and its interpretation has changed and been positioned at high levels. Although the role of quality in projects is critical, it has not been defined as well in general. Quality in projects has been addressed in numerous textbooks, international methodologies, and articles, yet it has not been harmonized. This conference paper covers the first part of a research project with the ultimate goal of a proper definition of quality in project management, which will allow us to measure and predict quality during project execution. For this purpose, we review the definitions of quality and the significant milestones in general and project management. So, deriving from the research project, the goal of this paper is to overview quality in project management by comparing it with the scientific position in quality management. This research provides all the necessary bases to serve the objectives mentioned above. Through the final research findings, we could suggest future research that will bring project management up to date not only in the quality definition but also in the practice of quality management.
Automation in Construction, 2021
Abstract Traditional Critical Path Method (CPM) and its different generalizations have become the... more Abstract Traditional Critical Path Method (CPM) and its different generalizations have become the prevailing technique in managing complex projects over recent decades. Among them, Precedence Diagramming Method (PDM), with its four precedence relationships, has become the most popular due to its increased flexibility in modeling complex project logic. Despite the four well-known precedence relationships, CPM/PDM still suffers from modeling shortcomings. Developments such as conditional logic, maximal relationships, point-to-point relationships, continuous relationships, and non-linear activities attempt to remedy these problems. However, these improvements require more complex and sometimes iterative time analysis. Monte Carlo (MC) simulation, which calculates the effects of risks on the project duration, also requires numerous repetitions of the deterministic time analysis. It is especially true if the network contains the developments mentioned above. In these cases, the time analysis speed is of great importance. The goal of this study is a) to implement different algorithms for time analysis that perform better than the traditional time analysis, b) to compare their speed on large-scale artificially created projects, c) to make suggestions regarding which algorithms are suitable in different cases d) to develop a database containing artificially created networks to serve as a basis for benchmarking for researchers and developers working in the field of project planning. Comparisons were based on networks with at least 1000 activities. Results show that, depending on the sample network's structure, different algorithms perform well. Therefore, different time analysis algorithms are necessary to implement into the scheduling tools, and they can decide which algorithms perform better.
The Journal of the Operational Research Society, 1999
International Journal of Construction Management
Procedia Engineering, 2015
This page was generated automatically upon download from the ETH Zurich Research Collection. For ... more This page was generated automatically upon download from the ETH Zurich Research Collection. For more information, please consult the Terms of use.
IOP Conference Series: Materials Science and Engineering, 2022
The literature of project success is very wide one. Various articles focus on the evolution of th... more The literature of project success is very wide one. Various articles focus on the evolution of the understanding of project success. Most of the projects we hear of in media are either over budget, late or are simply not good enough and still different lobbies of people claim that those projects have been successful. Neither the practitioners nor the academicians seem to agree on what constitutes project success. It seems to be a rather elusive concept. This paper attempts to put forth the points of views of different researchers in this field and focuses primarily on the factors that affect the project outcome regardless of the type of project. Two sets of factors contributed to successful outcome of a project: the macro and micro factors. A set of macro includes the realm of the owner, while micro factors fall in construction domain. Other factors were grouped into four areas: factors related to: project, project manager and team, organization, and the external environment. More f...
The Precedence Diagramming Method (PDM) is the prevalent scheduling technique used for temporal p... more The Precedence Diagramming Method (PDM) is the prevalent scheduling technique used for temporal planning of projects. Critical paths require special attention during the course of planning as their lengths define the project duration. However, increasing/decreasing the duration of an activity on the critical path does not necessarily results in a longer/shorter project duration. Responses of the critical path in a PDM network for small changes of the duration of a critical activity can be classified into six categories, while nine different possible categories exist in theory. The modeling capabilities of PDM recently have been extended by the introduction of a) point-to-point relations, b) continuous relations, and c) non-linear activity (production-time) functions. The paper presents the following conjecture that needs a proof: The number of existing types of critical activities remains six when using the recently developed precedence relations and non-linear production-time funct...
IOP Conference Series: Materials Science and Engineering, 2022
An influence line graphs for project planning show how the changes of a selected activity duratio... more An influence line graphs for project planning show how the changes of a selected activity duration affect the project duration. The name comes from the structural analysis where influence lines show on the ordinates of a graph the variation of the magnitude of, e.g., the bending moment at a specific point as a unit load traverses across the structure. This paper examines the principles of project planning influence lines: it discusses how to depict the six criticality types of activities, and it also shows what kind of transitions are possible among the criticality types. The findings help the greater understanding of the effects of the activity duration changes on the project duration.
Procedia - Social and Behavioral Sciences, 2013
Nonconvex optimization and its applications, 1997
Making the first version of a schedule, planners usually count with normal crew sizes on normal w... more Making the first version of a schedule, planners usually count with normal crew sizes on normal work days, that is, they count with normal activity duration times. If the calculated project duration is beyond the deadline, then it has to be decreased. The planner has two possibilities to compress the project time span within the given boundaries. First, he or she can change the precedence relationships, make more activities partially or completely concurrent, or organize the resources more efficiently, which can result in deleting some precedence relationships. The second possibility is to shorten the activity durations, as much as needed for the schedule to meet the deadline. It would be a great help to know how much can the project duration be shortened, i.e., what the minimum project duration is. If the schedule according to the minimum project duration is still behind the desired schedule, then the only solution is to change the network logic.
Procedia - Social and Behavioral Sciences, 2014
Nonconvex Optimization and Its Applications, 1997
Preface. 1. Introduction. 2. CPM Scheduling. 3. CPM Least Cost Scheduling. 4. Precedence Diagramm... more Preface. 1. Introduction. 2. CPM Scheduling. 3. CPM Least Cost Scheduling. 4. Precedence Diagramming. 5. Advanced Precedence Diagramming. 6. Precedence Diagramming with Bounded Activity Duration. 7. PDM Least Cost Scheduling. 8. Resources in Scheduling. 9. Art of Scheduling. Appendix A: Mathematical Basis. Appendix B: Computer Applications. Bibliography. Index.
Procedia - Social and Behavioral Sciences, 2013
Automation in Construction, 2013
Organization, Technology and Management in Construction: an International Journal, 2016
Modern project management owes its reputation to the development of modern scheduling techniques ... more Modern project management owes its reputation to the development of modern scheduling techniques based on the theory of graphs, namely, network scheduling techniques. In 2017, these techniques are celebrating their 60th birthday. This anniversary provides the opportunity to look back at the most important achievements such as non-linear activities and new precedence relations, as well as to take a look into the future. The highlights of this subjective retrospective are the presentation of the latest results and the compilation of those problems that will probably define the priorities for future research. This paper is the extended version of the keynote lecture/ presentation that has been presented at the PBE 2016 Conference (People, Buildings and Environment, Luhačovice, Czech Republic) (Hajdu 2016a).
A szerző a projekttervezes tortenetenek otveneves evforduloja, s talan mondhatjuk, hogy a projekt... more A szerző a projekttervezes tortenetenek otveneves evforduloja, s talan mondhatjuk, hogy a projektmenedzsment- tudomany/szakma szuletesenek otveneves evforduloja alkalmabol visszatekint a kezdetekre. A projektek tervezesenek fejlődesi folyamatait elemezve megkiserli a tapasztalhato trendek figyelembevetelevel a jovő fejlődesi iranyait megbecsulni.
The Gantt chart is the most widespread project planning method. Due to the development of project... more The Gantt chart is the most widespread project planning method. Due to the development of project management applications, more and more data can be assigned to the project plan. The options for handling new information have changed the purpose of creating a Gantt chart in many aspects. Moreover, we would like to manage all data in one place in the planning and in the tracking phases as well. As a result new aspects of analysis could also be introduced. In this paper, the Gantt chart is discussed from a brand-new point of view and novel methods are suggested in order to improve the management and understanding of the visual display. keywords: evaluation lines, project management, scheduling, tracking, visualization. ∗ Autor odpowiedzialny za korespondencje. E-mail: szenik.gabriella@ybl.szie.hu
Proceedings of the Creative Construction Conference 2023
The importance of quality is now recognized in every expertise. Quality management has significan... more The importance of quality is now recognized in every expertise. Quality management has significantly evolved over more than the last half-century, and the methods and techniques involved have been developed, their levels described in detail. During this evolutionary process, quality has been defined in several quality management sources, and its interpretation has changed and been positioned at high levels. Although the role of quality in projects is critical, it has not been defined as well in general. Quality in projects has been addressed in numerous textbooks, international methodologies, and articles, yet it has not been harmonized. This conference paper covers the first part of a research project with the ultimate goal of a proper definition of quality in project management, which will allow us to measure and predict quality during project execution. For this purpose, we review the definitions of quality and the significant milestones in general and project management. So, deriving from the research project, the goal of this paper is to overview quality in project management by comparing it with the scientific position in quality management. This research provides all the necessary bases to serve the objectives mentioned above. Through the final research findings, we could suggest future research that will bring project management up to date not only in the quality definition but also in the practice of quality management.
Automation in Construction, 2021
Abstract Traditional Critical Path Method (CPM) and its different generalizations have become the... more Abstract Traditional Critical Path Method (CPM) and its different generalizations have become the prevailing technique in managing complex projects over recent decades. Among them, Precedence Diagramming Method (PDM), with its four precedence relationships, has become the most popular due to its increased flexibility in modeling complex project logic. Despite the four well-known precedence relationships, CPM/PDM still suffers from modeling shortcomings. Developments such as conditional logic, maximal relationships, point-to-point relationships, continuous relationships, and non-linear activities attempt to remedy these problems. However, these improvements require more complex and sometimes iterative time analysis. Monte Carlo (MC) simulation, which calculates the effects of risks on the project duration, also requires numerous repetitions of the deterministic time analysis. It is especially true if the network contains the developments mentioned above. In these cases, the time analysis speed is of great importance. The goal of this study is a) to implement different algorithms for time analysis that perform better than the traditional time analysis, b) to compare their speed on large-scale artificially created projects, c) to make suggestions regarding which algorithms are suitable in different cases d) to develop a database containing artificially created networks to serve as a basis for benchmarking for researchers and developers working in the field of project planning. Comparisons were based on networks with at least 1000 activities. Results show that, depending on the sample network's structure, different algorithms perform well. Therefore, different time analysis algorithms are necessary to implement into the scheduling tools, and they can decide which algorithms perform better.
The Journal of the Operational Research Society, 1999
International Journal of Construction Management
Procedia Engineering, 2015
This page was generated automatically upon download from the ETH Zurich Research Collection. For ... more This page was generated automatically upon download from the ETH Zurich Research Collection. For more information, please consult the Terms of use.
IOP Conference Series: Materials Science and Engineering, 2022
The literature of project success is very wide one. Various articles focus on the evolution of th... more The literature of project success is very wide one. Various articles focus on the evolution of the understanding of project success. Most of the projects we hear of in media are either over budget, late or are simply not good enough and still different lobbies of people claim that those projects have been successful. Neither the practitioners nor the academicians seem to agree on what constitutes project success. It seems to be a rather elusive concept. This paper attempts to put forth the points of views of different researchers in this field and focuses primarily on the factors that affect the project outcome regardless of the type of project. Two sets of factors contributed to successful outcome of a project: the macro and micro factors. A set of macro includes the realm of the owner, while micro factors fall in construction domain. Other factors were grouped into four areas: factors related to: project, project manager and team, organization, and the external environment. More f...
The Precedence Diagramming Method (PDM) is the prevalent scheduling technique used for temporal p... more The Precedence Diagramming Method (PDM) is the prevalent scheduling technique used for temporal planning of projects. Critical paths require special attention during the course of planning as their lengths define the project duration. However, increasing/decreasing the duration of an activity on the critical path does not necessarily results in a longer/shorter project duration. Responses of the critical path in a PDM network for small changes of the duration of a critical activity can be classified into six categories, while nine different possible categories exist in theory. The modeling capabilities of PDM recently have been extended by the introduction of a) point-to-point relations, b) continuous relations, and c) non-linear activity (production-time) functions. The paper presents the following conjecture that needs a proof: The number of existing types of critical activities remains six when using the recently developed precedence relations and non-linear production-time funct...
IOP Conference Series: Materials Science and Engineering, 2022
An influence line graphs for project planning show how the changes of a selected activity duratio... more An influence line graphs for project planning show how the changes of a selected activity duration affect the project duration. The name comes from the structural analysis where influence lines show on the ordinates of a graph the variation of the magnitude of, e.g., the bending moment at a specific point as a unit load traverses across the structure. This paper examines the principles of project planning influence lines: it discusses how to depict the six criticality types of activities, and it also shows what kind of transitions are possible among the criticality types. The findings help the greater understanding of the effects of the activity duration changes on the project duration.
Procedia - Social and Behavioral Sciences, 2013
Nonconvex optimization and its applications, 1997
Making the first version of a schedule, planners usually count with normal crew sizes on normal w... more Making the first version of a schedule, planners usually count with normal crew sizes on normal work days, that is, they count with normal activity duration times. If the calculated project duration is beyond the deadline, then it has to be decreased. The planner has two possibilities to compress the project time span within the given boundaries. First, he or she can change the precedence relationships, make more activities partially or completely concurrent, or organize the resources more efficiently, which can result in deleting some precedence relationships. The second possibility is to shorten the activity durations, as much as needed for the schedule to meet the deadline. It would be a great help to know how much can the project duration be shortened, i.e., what the minimum project duration is. If the schedule according to the minimum project duration is still behind the desired schedule, then the only solution is to change the network logic.
Procedia - Social and Behavioral Sciences, 2014
Nonconvex Optimization and Its Applications, 1997
Preface. 1. Introduction. 2. CPM Scheduling. 3. CPM Least Cost Scheduling. 4. Precedence Diagramm... more Preface. 1. Introduction. 2. CPM Scheduling. 3. CPM Least Cost Scheduling. 4. Precedence Diagramming. 5. Advanced Precedence Diagramming. 6. Precedence Diagramming with Bounded Activity Duration. 7. PDM Least Cost Scheduling. 8. Resources in Scheduling. 9. Art of Scheduling. Appendix A: Mathematical Basis. Appendix B: Computer Applications. Bibliography. Index.
Procedia - Social and Behavioral Sciences, 2013
Automation in Construction, 2013
Organization, Technology and Management in Construction: an International Journal, 2016
Modern project management owes its reputation to the development of modern scheduling techniques ... more Modern project management owes its reputation to the development of modern scheduling techniques based on the theory of graphs, namely, network scheduling techniques. In 2017, these techniques are celebrating their 60th birthday. This anniversary provides the opportunity to look back at the most important achievements such as non-linear activities and new precedence relations, as well as to take a look into the future. The highlights of this subjective retrospective are the presentation of the latest results and the compilation of those problems that will probably define the priorities for future research. This paper is the extended version of the keynote lecture/ presentation that has been presented at the PBE 2016 Conference (People, Buildings and Environment, Luhačovice, Czech Republic) (Hajdu 2016a).
A szerző a projekttervezes tortenetenek otveneves evforduloja, s talan mondhatjuk, hogy a projekt... more A szerző a projekttervezes tortenetenek otveneves evforduloja, s talan mondhatjuk, hogy a projektmenedzsment- tudomany/szakma szuletesenek otveneves evforduloja alkalmabol visszatekint a kezdetekre. A projektek tervezesenek fejlődesi folyamatait elemezve megkiserli a tapasztalhato trendek figyelembevetelevel a jovő fejlődesi iranyait megbecsulni.
The Gantt chart is the most widespread project planning method. Due to the development of project... more The Gantt chart is the most widespread project planning method. Due to the development of project management applications, more and more data can be assigned to the project plan. The options for handling new information have changed the purpose of creating a Gantt chart in many aspects. Moreover, we would like to manage all data in one place in the planning and in the tracking phases as well. As a result new aspects of analysis could also be introduced. In this paper, the Gantt chart is discussed from a brand-new point of view and novel methods are suggested in order to improve the management and understanding of the visual display. keywords: evaluation lines, project management, scheduling, tracking, visualization. ∗ Autor odpowiedzialny za korespondencje. E-mail: szenik.gabriella@ybl.szie.hu