| 1. |
- Akillioglu, Hakan, et al.
(author)
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Characterization of continuous precise workload control and analysis of idleness penalty
- 2016
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In: Computers & industrial engineering. - : Elsevier. - 0360-8352 .- 1879-0550. ; 102, s. 351-358
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Journal article (peer-reviewed)abstract
- The variability in the market conditions is growing in terms of its frequency of change and range of diversity. In response to this new industrial panorama, research on production systems is aiming to achieve highly reconfigurable shop floors. Frequent changes in such systems require also frequent re-planning with updated information. In this regard the Continuous Precise Workload Control method, is a recent approach aiming at precise control of workload in shop floor with the use of direct load graphs. Supported by a multi-agent platform, it generates dynamic non-periodic release decisions exploiting real time shop floor information. The study in this paper is two folded; (1) the presented workload approach is defined in terms of eight dimensions of the workload control concept in order to highlight its distinctive characteristics and (2) the impact of idleness penalty factor is analyzed by an experiment design in order to investigate its effect on the job release decision. The results show that the idleness penalty factor decreases the idleness of the resources up to a point where the adverse effect is initiated.
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| 2. |
- Akillioglu, Hakan, 1983-, et al.
(author)
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Characterization of Continuous Precise Workload Control and Analysis of Idleness Penalty
- 2014
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In: CIE 44 and IMSS14 proceedings. ; , s. 1998-2011
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Conference paper (peer-reviewed)abstract
- The variability in the market conditions is growing in terms of its frequency of change and range of diversity. In response to this new industrial panorama, research on production systems is aiming to achieve truly reconfigurable shop floors. Frequent changes in such systems require also frequent re-planning with updated information. In this regard the Continuous Precise Workload Control method, is a recent approach aiming at precise control of workload in the shop floor with the use of direct load graphs. Supported by a multi-agent platform, it generates dynamic non-periodic release decisions exploiting real time shop floor information. The study in this paper is two folded; (1) in order to highlight its distinctive characteristics, the presented workload approach is defined in terms of eight dimensions of the workload control concept and (2) the penalty of idleness which affects the decision of release is analyzed by an experiment design in order to investigate its correlation with two critical parameters, norm value and assessment range. The results show that the idleness penalty factor decreases the idleness of the resources up to a point where the adverse effect is initiated. Besides there are strong indications towards the correlation of idleness penalty factor with the norm value.
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| 3. |
- Akillioglu, Hakan, et al.
(author)
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Continuous precise workload control method
- 2014
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In: IEEE International Conference on Industrial Engineering and Engineering Management. - 9781479964109 ; , s. 511-515
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Conference paper (peer-reviewed)abstract
- The diversity of requirements and the frequency of change in the market can only be competed with dynamicity and responsiveness in both production and planning systems. In this sense, working principles of a novel workload control method, called continuous precise workload control are presented in this paper. The implementation of the method is based on a multi-agent based architecture. The presented approach generates dynamic non periodic release decisions exploiting real time shop floor information. The performance of the system and correlation of norm value against the assessment range are investigated through an experimented test case.
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| 4. |
- Akillioglu, Hakan, 1983-
(author)
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Demand Responsive Planning : A dynamic and responsive planning framework based on workload control theory for cyber-physical production systems
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Recent developments in the area of Cyber-Physical Production Systems prove that high technology readiness level is already achieved and industrialization of such technologies is not far from today. Although these technologies seem to be convenient in providing solutions to environmental uncertainties, their application provides adaptability only at shop floor level. Needless to say, an enterprise cannot reach true adaptability without ensuring adaptation skills at every level in its hierarchy. Commonly used production planning and control approaches in industry today inherit from planning solutions which are developed in response to historical market characteristics. However, market tendency in recent years is towards making personalized products a norm. The emerging complexity out of this trend obliges planning systems to a transition from non-recurring, static planning into continuous re-planning and re-configuration of systems. Therefore, there is a need of responsive planning solutions which are integrated to highly adaptable production system characteristics.In this dissertation, Demand Responsive Planning, DRP, is presented which is a planning framework aiming to respond to planning needs of shifting trends in both production system technologies and market conditions. The DRP is based on three main constructs such as dynamicity, responsiveness and use of precise data. These features set up the foundation of accomplishing a high degree of adaptability in planning activities. By this means, problems from an extensive scope can be handled with a responsive behavior (i.e. frequent re-planning) by the use of precise data. The use of precise data implies to execute planning activities subject to actual demand information and real-time shop floor data. Within the context of the DRP, both a continuous workload control method and a dynamic capacity adjustment approach are developed. A test-bed is coded in order to simulate proposed method based on a system emulation reflecting the characteristics of cyber-physical production systems at shop floor level.Continuous Precise Workload Control, CPWLC, method is a novel approach aiming at precise control of workload levels with the use of direct load graphs. Supported by a multi-agent platform, it generates dynamic non-periodic release decisions exploiting real time shop floor information. As a result, improved shop floor performances are achieved through controlling workload levels precisely by the release of appropriate job types at the right time.Presented dynamic capacity adjustment approach utilizes rapid re-configuration capability of cyber-physical systems in achieving more frequent capacity adjustments. Its implementation architecture is integrated to the CPWLC structure. By this means, a holistic approach is realized whereby improved due date performance is accomplished with minimized shop floor congestion. Hence, sensitivity to changing demand patterns and urgent job completions is improved.
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| 5. |
- Akillioglu, Hakan, 1983-, et al.
(author)
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Demand responsive planning : workload control implementation
- 2013
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In: Assembly Automation. - UK : Emerald Group Publishing Limited. - 0144-5154 .- 1758-4078. ; 33:3, s. 247-259
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Journal article (peer-reviewed)abstract
- Purpose – Evolvable production systems enable fully reconfiguration capabilities on the shop floor through process-oriented modularity and multiagent-based distributed control. To be able to benefit architectural and operational characteristics of evolvable systems, there is a need of a newplanning approach which links shop floor characteristics and planning operations. This paper seeks to address these issues.Design/methodology/approach – Evolvable production system has a structured methodology in itself. Consistent to this, a reference planningarchitecture is developed aiming to achieve agility on planning activities. Besides a workload control method is proposed and implemented as a part ofthe planning architecture.Findings – First applications of evolvable systems have been implemented through European research projects. Shop floor working principles andarchitectural characteristics are consistent to facilitate more agility on planning activities which are framed at a planning reference architecture calleddemand responsive planning. As an implementation case, an agent-based workload control method is proposed and implemented. The characteristicsof EPS and proposed planning architecture enable continuous and dynamic workload control of the shop floor to be implemented.Originality/value – This paper presents a new planning model compatible with evolvable production systems targeting to agility to demand onplanning and control activities benefiting shop floor enhancements of a fully reconfigurable system which enables to relax constraints imposed fromproduction systems to planning. In addition, a continuous and dynamic workload control method is proposed and implemented.
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| 6. |
- Akillioglu, Hakan, 1983-, et al.
(author)
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Evolvable Assembly Systems: Mechatronic Architecture Implications and Future Research
- 2010
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Conference paper (peer-reviewed)abstract
- The balance between assembly process optimality and their system’s ability to adapt to new requirements is a key to success for assembly companies. To increase SME’s survivability, an effective methodology is needed to handle the requirements of both agility and mass customization. Evolvable Assembly Systems (EAS) paradigm is a next generation assembly systems focused on these issues. Three key issues are here in focus: process-oriented approach, fine modular granularity, and module intelligence through lighter multi-agent technology at the shop floor level. These issues
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| 7. |
- Akillioglu, Hakan, et al.
(author)
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Evolvable production systems and impacts on production planning
- 2011
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Conference paper (other academic/artistic)abstract
- Production planning and control strategies have been changing in line with the constant change on product and customer requirements, under the light of technological and scientific advancements. Production systems which are based on mass production became obsolete in time hence companies, being profit oriented, are in need of new solutions towards mass customization to handle rapidly changing market conditions. To deal with this issue, production systems and production planning strategies have to be complementing each other. In this paper Evolvable Production Systems and its compatibility to Just in Time (JIT) Production compared to Material Requirement Planning (MRP) will be discussed.
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| 8. |
- Akillioglu, Hakan, 1983-
(author)
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Evolvable Production Systems: Demand Responsive Planning
- 2011
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Licentiate thesis (other academic/artistic)abstract
- Dynamic and unforeseeable characteristic of the current market and production environment is not feasible to be met through pre-set parameters being dependent on the predictions. Handling this matter requires to keep focus on production system adaptability. Evolvable Production System has achieved fully system reconfigurability through process oriented modularity and multi agent based distributed control system architecture. One of the essential enhancements provided by EPS on the shop floor is achieving minimized/eliminated system setup time in response to changing product requirements.Manufacturing planning and control system, on the other hand, follows hierarchical principles which are quite much reliant on the predicted information so to structure production and planning environment on it. Production system limitations, such as lack of adaptability in response to changing conditions, are in fact influencing the planning system to be structured on the predictions. The enhancements which are ensured by the architecture of EPS enable to relax the constraints on planning system which are imposed by the limitations of production system. These enhancements have an effect at different levels in the planning hierarchy. On the light of these improvements, the planning framework as it is used so far in the industry becomes invalid and this arise a requirement for planning system structure to be designed according to a fully reconfigurable system to be able to benefit such a production system by all means.This thesis targets to enlighten the relation between the production system characteristics and planning system structure by emphasizing the planning problems and proposing a planning reference architecture solution to be able achieve a responsive planning framework.
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| 9. |
- Alsterman, Henric, et al.
(author)
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Definitions, Limitations and Approaches to Evolvable Assembly System Platforms
- 2005
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In: Emerging Solutions for Future Manufacturing Systems. - Boston : Kluwer Academic Publishers. - 0387228284 - 0387228292 ; , s. 367-378
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Conference paper (peer-reviewed)abstract
- Europe, as most other OECD areas, is confronted with major potential opportunities in the decades to come. Although often portrayed as threats, the symptoms being denoted in the European economy are, in fact, part of a shift in knowledge and technology infrastructures created by these trends. These current challenges being faced by manufacturing companies nowadays require production systems to become ever more responsive and agile. This is particularly relevant to micro-products, since manual assembly becomes impossible, rendering outsourcing strategies less effective if not deliberately negative. Furthermore, traditional approaches to R&D in this field no longer suffice to cope with the challenges imposed since these imply new business methods, continuous technological evolution, and the increased tendency towards networks of enterprises.To meet such demands there is a need for new rapidly deployable and affordable (economically sustainable) microassembly systems based on reconfigurable, modular concepts that would allow continuous system evolution and seamless reconfiguration. Furthermore, as will be detailed later, one of the required foundations to sustainable assembly system concepts lies within a new way of thinking and working: a methodology that could integrate the various aspects related to the life cycle of the production systems, with particular focus being placed on the re-engineering phase. This article will present some definitions, clarify the basic approach, and outline the serious requirements being posed by such a paradigm: Evolvable Assembly Systems.
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| 10. |
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