Design. Analyze. Optimize.

Conference Papers and Seminar Publications


Availability modeling approach for future circular colliders based on the LHC operation experience

Niemi A, Apollonio A, Gutleber J, Sollander P, CERN
Penttinen J-P, Ramentor Oy
Virtanen S, Tampere University of Technology

Physical Review Accelerators and Beams 19, 121003
27 December, 2016

"Reaching the challenging integrated luminosity production goals of a future circular hadron collider (FCC-hh) and high luminosity LHC (HL-LHC) requires a thorough understanding of today’s most powerful high energy physics research infrastructure, the LHC accelerator complex at CERN. This paper introduces the FCC reliability and availability study, which takes a fresh new look at assessing and modeling reliability and availability of particle accelerator infrastructures. ELMAS version 4.8, used for this study, permits specifying production functions, semi-Markov chain transition logic and conditional operation schedule specifications with user-specific Java snippets."

URL: https://doi.org/10.1103/PhysRevAccelBeams.19.121003


Advanced Fault Tree Analysis for Improved Quality and Risk Assessment

Penttinen J-P, Ramentor Oy
Lehtinen T, Ramentor Oy

10th World Congress on Engineering Asset Management (WCEAM 2015)
26 March, 2016

"Traditional fault tree analysis (FTA) has formed a common language for the modelling and analysis of risks of complex systems. The approach can be used for a large variety of cases, and several tools exists for the method. Advanced FTA is needed to apply the FTA approach also for dynamic systems with time dependent activities. The traditional FTA is extended by including for example modelling and simulation of operation or phase changes of the systems, stochasticity and delays of relations, and maintenance actions for the components. The rules between the failures and other simulated properties are defined by including Java-based scripts to the model. This allows a great freedom to model any type of dynamic situations. A tool named ELMAS has been created to make the use of the advanced FTA approach as straightforward as possible. It allows to model the static and simple relations by using the traditional FTA method. Complex and dynamic relations are included by using modules that can be freely defined based on the needs of the case."

URL: http://link.springer.com/chapter/10.1007/978-3-319-27064-7_45


Advanced RCM Industry Case - Modeling and Advanced Analytics (ELMAS) for improved availability and cost-efficiency

Tammi M, Ramentor Oy
Vuorela V, Ramentor Oy
Lehtinen T, Ramentor Oy

10th World Congress on Engineering Asset Management (WCEAM 2015)
26 March, 2016

"Today there are several well-proven analysis methods available for reliability and maintenance management. Most of them are however developed for analyzing safety-critical applications. Within basic industry the focus is typically on cost management and traditional analysis methods are often presumed as too laborious. This seminar paper is based on an ELMAS reliability analysis per-formed for a production-critical molding crane in metals industry at SSAB Raahe factory in Finland. The main objective was to identify risks and optimize mainte-nance actions in a cost-effective manner. Another objective was to develop a sys-tematic procedure for managing cost risks of production-critical process parts. The analysis combines the main benefits of fault tree analysis (FTA), failure mode and effect analysis (FMEA) and reliability centered maintenance (RCM) to form a sys-tematic method for performing versatile analysis and corrective action planning."

URL: http://link.springer.com/chapter/10.1007/978-3-319-27064-7_58


Spare Part Stock Modeling and Cost Optimization

Turpela J, Ramentor Oy
Lehtinen T, Ramentor Oy

10th World Congress on Engineering Asset Management (WCEAM 2015)
26 March, 2016

"Modeling and planning the spare part item stock is a quite complex, but utmost rewarding task regarding the operational excellence of a manufacturing industry company. The challenge with the design is derived from multi-variable optimization tasks, including e.g. consumption rate of an item, division of stocking costs, and potential shortage costs. This applies especially in case of new spare part item with no history data for defining the consumption rate."

URL: http://link.springer.com/chapter/10.1007/978-3-319-27064-7_61


Application of Design Review to Probabilistic Risk Assessment in a Large Investment Project

Virtanen S, Tampere University of Technology
Penttinen J-P, Ramentor Oy
Kiiski M, Jokinen J, Pöyry Finland Oy

Probabilistic Safety Assessment and Management PSAM 12
22-27 June, 2014

"In this paper, we present a systematic and comprehensive Design Review (DR) process that is integrated in design and engineering stages of final disposal facilities of spent nuclear fuel. The review process consists of seventeen interconnected phases and in the paper the methodology of certain phases is described in more detail."

URL: http://psam12.org/proceedings/paper/paper_319_1.pdf


Integrated Business and Technical Product Reliability Design

Virtanen S, Tampere University of Technology

Seminar of BRED-project (Association of research and development of electronics KOTEL ry)
Espoo
31 December, 2008

"The traditional and still dominating method for product design is focused on optimising the technical performance of a product. The reason for this is simple, there is no easily available and comprehensive design method or tool to integrate the reliability and maintainability (R&M) considerations and effects in product design. As more the companies’ management have experienced the meaning of Product’s R&M as competitive factors in their business, as more they have started to invest R&M engineering and development. This was also a starting point from where this project was launched."


Product Reliability and Availability in Field Data

Nevavuori L, Service Development, KONE Corporation

Proceedings of the 3rd World Congress on Engineering Asset Management and Intelligent Maintenance Systems (WCEAM-IMS 2008)
Beijing, China
27-30 October, 2008

"Demands for the dependability have risen in the elevator industry during the recent years. The aim of the paper is to introduce a case study that was performed by KONE’s reliability and maintenance departments in the beginning of year 2007. The case is about products’ perceived dependability follow-up. Moreover, a target is to present how reliability data was collected as well as utilized in reliability centered maintenance planning. In this case the starting point for a dependability follow-up was the back reported field data from maintenance actions."


Simulation and Calculation of Reliability Performance and Maintenance Costs

Hagmark P-E, Ph.D., Tampere University of Technology
Virtanen S, Ph.D., Tampere University of Technology

Annual Reliability and Maintainability Symposium (RAMS)
Orlando, FL, USA
22-25 January, 2007

"Our model for the simulation and calculation of reliability performance and maintenance costs is based on a generalized fault tree approach, where the TOP represents the product to be designed. The fault tree consists of entities, which essentially affect the failure tendency and the repair time of the product. The relations between entities are modeled by two mechanisms. The “gates” determine the partly logical and partly stochastic propagation of faults (primary states). The “strategies” define other relations between TOP and the deepest entities. A consequence of the strategies is that two types of “waiting” (secondary states) can occur."


Risk evaluation of a spare part stock by stochastic simulation

Hagmark P-E, Ph.D., Tampere University of Technology
Pernu H, M.Sc., Tampere University of Technology

ESREL 2006 Conference, Safety and Reliability for Managing Risk
Estoril, Portugal
18-22 September, 2006

"Spare part inventories are necessities in keeping equipment in operating condition. The design of a spare part inventory is risk management by nature. It is a multi-phase task to meet the associated economical and technical requirements. A typical target is to optimize the size of the stock by balancing the costs against the stock-out risk. This paper is a brief presentation of an effort toward a broad-based methodology. Our model can be characterized as a simulation-calculation scheme that connects organically inventory design, process redundancy, maintenance policy, spare part reliability & demand, and shortage & cost accounting. The multitude of variables and concepts in our model enables a vast number of interpretations. Since the sub-models imitate the reality in time order, the model is easy to extend when new knowledge or new features need to be taken into account. The corresponding and still developing software extends continuously the applicability. At present, a tool for the optimization of selected cost combinations has been implemented."


Modeling and analysis of causes and consequences of failures

Virtanen S, Ph.D., Tampere University of Technology
Hagmark P-E, Ph.D., Tampere University of Technology
Penttinen J-P, M.Sc., Tampere University of Technology

Annual Reliability and Maintainability Symposium (RAMS)
Newport Beach, CA, USA
23-26 January, 2006

"Modeling and analysis of causes and consequences of failures form a foundation for quantitative investigation of the reliability, safety and risks related to a design entity. The general term “entity” or “design entity” can stand for function, system, equipment, mechanism, or any kind of part."


Specification and Allocation of Reliability and Availability Requirements

Hagmark P-E, Ph.D., Tampere University of Technology
Virtanen S, Ph.D., Tampere University of Technology

Annual Reliability and Maintainability Symposium (RAMS)
Newport Beach, CA, USA
23-26 January, 2006

"This paper presents, a computer-supported method for specifying reliability, repair time, and availability requirements for a product and allocating them into the product’s design entities. The general term “entity” can stand for function, system, equipment, mechanism, or any kind of part."


Reliability Engineering and Maintenance in Finnish Industry

Virtanen S, Ph.D., Tampere University of Technology

July, 2005

"New product liability legislation, enhanced competition, and economizing on expenditures have lent increased importance to technical considerations of reliability and maintainability in product design. A product’s reliability and maintainability (R&M) are quality characteristics to which where customers attach great importance when forming an opinion of product’s overall quality. It is especially important to understand that these are precisely the characteristics whose design flaws cannot be fixed during manufacturing or operation. In fact we might say that it is in the product design phase where the fundamental decisions are made to set the product’s quality maximum and cost minimum. A company that has a good control of the R&M performance for its products has a considerable competitive advantage both in the case of design and manufacturing consumer products and when negotiating about availability contracts for large industrial systems."