Magnus Karlberg

A development process for Functional Products: hardware, software, service support system and management of operation

The development process for a Functional Product (FP) is complex and there is a need to coordinate, monitor, control and share information as well as to communicate properly among the parties involved in the process. This paper proposes a conceptual development process to manage the FP development, including development of hardware, software, service support system and how to manage the operation of an FP. Further, challenges related to the integrated development of FPs are also discussed.

Functional product system availability : simulation driven design and operation through coupled multi-objective optimisation

This paper describes on a conceptual level how the availability of functional products (consisting of hardware (HW) and a support system) may be simulated. The main objective of this paper is to present a simulation-driven methodology for predicting and optimising the availability and cost of functional products in both development and operation. The proposed simulation and optimisation methodology includes both HW and support system models, which coupled form a simulation model of a system (functional product) delivering the function. Two different simulation-driven methodologies are suggested in the paper: one for development and another for operation of functional products.

Functional Product development: what information should be shared during the development process?

The development process for a Functional Product (FP) is complex and there is a need to share information as well as to communicate it among the parties involved in the process. The paper concerns shared information that is of specific interest when developing FPs, in contrast to information that must be shared during a general product or service development process. The findings are compiled in a conceptual table comprising such specific information items pertaining to both the initial development as well as post development parts of an FPs lifecycle. This table can be used as an aid to any development process or method, as it points out information items that must necessarily be shared, but not how they to be shared.

Numerical investigation of an unbalanced rotor system with bearing clearance

Abstract The nonlinear vibrations of a rotor system with bearing clearance are considered. The model consists of an unbalanced shaft with two d.o.f connected to a nonrotating massless housing by linear springs and dashpots. The clearance occurs when the housing (modelled as a ring) has a radius less than the stator. The behaviour of this system has been investigated with the use of time histories, Poincare maps, bifurcation diagrams, Lyapunov exponents, phase portraits, cell mapping and design space. Numerical simulations have achieved these results. The main objective was to find possible causes of failure in machines containing this type of clearance. The existence of subharmonic, quasi-periodic or even possible chaotic motion has been found. It is shown that these motions may give raise to bouncing modes, which results in high bearing forces and hence can be a possible cause of failure.

State of the art in simulation-driven design

During the last few decades, and in order to increase product development efficiency, simulations strategies have been developed to guide designers towards better solutions rather than to verify suggested and basically unevaluated solutions. Such approaches are often called Simulation-Driven Design (SDD), which is of interest in this review. The objective of this paper is to show the research evolution of SDD and identify the state of the art in SDD methodology. The literature review comprises several hundred references, of which 79 are included in this paper. The results comprise the state of the art in SDD including the history, various definitions, criteria and effects of using SDD approaches.

Modelling service support system reliability

Functional Products, where the customer pays for the function and availability of a product instead of the product itself, are increasingly popular in capital intensive industries such as aerospace. Such products are integrated systems involving the combination of hardware and service support systems. The reliability prediction and optimisation of the service system that supports the hardware availability is essential to the feasibility of the product. These systems consist of maintenance procedures and resource provisions. Simulation based techniques are presented in this paper to analyse the reliability of support systems and their application is demonstrated through a simple example.

Data Stream Mining for Increased Functional Product Availability Awareness

Functional Products (FP) and Product Service Systems (PSS) may be seen as integrated systems comprising hardware and support services. For such offerings, availability is key. Little research has been done on integrating Data Stream Management Systems (DSMS) for monitoring (parts of) a FP to improve system availability. This paper introduces an approach for how data stream mining may be applied to monitor hardware being part of a Functional Product. The result shows that DSMS have the potential to significantly support continuous availability awareness of industrial systems, especially important when the supplier is to supply a function with certain availability.

Modelling and simulation of functional product system availability and support costs

Functional Products (FP), total offers or product service systems that comprise of both Hardware (HW) and Support Services (SS) sold as an integrated offering under an availability guarantee are becoming increasing popular in industry. This paper addresses, through modelling and simulation the challenge faced by suppliers in developing an integrated HW and SS design to produce an FP which meets contracted availability. A recently published framework specified how an integrated model hardware and service support system model could be used to obtain functional availability predictions and perform simulation driven functional product development. This paper presents the first example of an integrated functional product model. It uses fault tree, Petri net and discrete event simulation techniques to enable the prediction of functional product availability and support costs. Such predictions are used here to evaluate and compare different service support system designs.

A METHOD TO IMPROVE EFFICIENCY IN WELDING SIMULATIONS FOR SIMULATION DRIVEN DESIGN

Welding is one of the most commonly used methods of joining metal pieces. In product development it is often desirable to predict residual stresses and distortions to verify that e.g., alignment tolerances, strength demands, fatigue requirements, stress corrosion cracking, etc. are fulfilled. The objective of this paper is to derive a strategy to improve the efficiency of welding simulations aiming at a (future) simulation-driven design methodology. In this paper, a weld bead deposition technique called block dumping has been applied to improve the efficiency. The proposed strategy is divided into seven steps, where the first four steps are verified by two welding simulation cases (a benchmark problem for a single weld bead-on-plate specimen and a T-welded structure). This study shows that by use of the block dumping technique, the computation time can be reduced by as much as 93% compared to moving heat source, still with acceptable accuracy of the model.Copyright

Reliability Prediction Based on Variation Mode and Effect Analysis

The possibility of predicting the reliability of hardware for both components and systems is important in engineering design. Today, there are several methods for predicting the reliability of hard ...