The currently low requirements on sound emissions for industrial trucks are expected to be raised in the near future. The company Kalmar Industries AB, which develop, produce and market industrial trucks, want to improve their truck silencers as a precaution to the future harder restrictions and also to improve their competitiveness. The sound emission produced by a vehicle depends on type and range of application it is designed for but the dominant part of the sound is usually produced by the engine and silencer. A new measuring method is developed for studying sound emanating through the silencer system. The analysis of the measurement data establishes that the silencers are not working well. The simulations made with SIDLAB, which is a computer programme for calculating the propagation of sound in ducts, confirms that the silencers are inefficient and that they are simply too small. A simulation which implements a parallel resonator in the main silencer shows that it is possible to make great improvements in reducing the noise from the truck as well as meeting requirements on space. Mathematical modelling based on linearity and one-dimensional interaction between the silencer elementsis advantageous and gives very good results when understanding, analysing and simulating the silencer. The simulation tool SIDLAB works well and saves a lot of time by its fast modelling and easy interface.

<p>The currently low requirements on sound emissions for industrial trucks are expected to be raised in the near future. The company Kalmar Industries AB, which develop, produce and market industrial trucks, want to improve their truck silencers as a precaution to the future harder restrictions and also to improve their competitiveness. The sound emission produced by a vehicle depends on type and range of application it is designed for but the dominant part of the sound is usually produced by the engine and silencer.</p><p>A new measuring method is developed for studying sound emanating through the silencer system. The analysis of the measurement data establishes that the silencers are not working well. The simulations made with SIDLAB, which is a computer programme for calculating the propagation of sound in ducts, confirms that the silencers are inefficient and that they are simply too small.</p><p>A simulation which implements a parallel resonator in the main silencer shows that it is possible to make great improvements in reducing the noise from the truck as well as meeting requirements on space.</p><p>Mathematical modelling based on linearity and one-dimensional interaction between the silencer elementsis advantageous and gives very good results when understanding, analysing and simulating the silencer. The simulation tool SIDLAB works well and saves a lot of time by its fast modelling and easy interface.</p>

The main purpose of this thesis is to develop a new model which helps the decision maker to rationalize outsourcing decisions based on Life Cycle Cost (LCC) analysis and select the appropriate supplier. The model developed consists of four main phases, as well as a pre-evaluating step, which investigate the organization needs and circumstances. Phase I is an evaluation and calculation phase, it assess whether outsourcing is the right policy to be adopted as a competitive advantage from two perspectives; the strategic evaluation of the outsourcing decision, and the cost savings through the life time of the outsourcing process using LCC. Phase II is supplier's selection; it aims to select the preferred supplier using Multiple Criteria Decision Making (MCDM), as well as identifies performance measures to monitor supplier performance. Phase III is maintain and monitor phase, it aims to keep the process and the supplier under continuous revision and assessment. Phase IV is review phase, it aims to identify if a specified monitored parameter is out of control or at critical levels, and identify the causes. This model contribute in covering the lack in the literature by considering LCC in the outsourcing decision making, as well as providing a structured model that concern about the whole process starting by understanding the organizations need and ends by monitoring and review the outsourcing process. The model was validated at one Swedish company, i.e. Kalmar Industries in Ljungby assembly unit, in particular, within the maintenance department. The results of the model validation shows that using LCCA, and risk benefits associated, the preferred alternative is to outsource all the maintenance activities related to ventilation system, these activates involve maintenance personnel, spare parts, and third party to monitor and report the process to authorities. Furthermore, based on LCCA and other suggested criteria and using MCDM, ABB Supplier got the lowest score in MCDM i.e. 36.70% (the lowest LCC along with fulfillment of the qualitative criteria). The main result is that; it is possible to employ LCCA in the maintenance outsourcing process to achieve a strategic model valid for decisions taking over the life length of the process. Consequently, the main recommendation for the case company is to outsource these activities and to transfer it to ABB service supplier.

<p>The main purpose of this thesis is to develop a new model which helps the decision maker to rationalize outsourcing decisions based on Life Cycle Cost (LCC) analysis and select the appropriate supplier. The model developed consists of four main phases, as well as a pre-evaluating step, which investigate the organization needs and circumstances. Phase I is an evaluation and calculation phase, it assess whether outsourcing is the right policy to be adopted as a competitive advantage from two perspectives; the strategic evaluation of the outsourcing decision, and the cost savings through the life time of the outsourcing process using LCC. Phase II is supplier's selection; it aims to select the preferred supplier using Multiple Criteria Decision Making (MCDM), as well as identifies performance measures to monitor supplier performance. Phase III is maintain and monitor phase, it aims to keep the process and the supplier under continuous revision and assessment. Phase IV is review phase, it aims to identify if a specified monitored parameter is out of control or at critical levels, and identify the causes. This model contribute in covering the lack in the literature by considering LCC in the outsourcing decision making, as well as providing a structured model that concern about the whole process starting by understanding the organizations need and ends by monitoring and review the outsourcing process.</p><p>The model was validated at one Swedish company, i.e. Kalmar Industries in Ljungby assembly unit, in particular, within the maintenance department. The results of the model validation shows that using LCCA, and risk benefits associated, the preferred alternative is to outsource all the maintenance activities related to ventilation system, these activates involve maintenance personnel, spare parts, and third party to monitor and report the process to authorities. Furthermore, based on LCCA and other suggested criteria and using MCDM, ABB Supplier got the lowest score in MCDM i.e. 36.70% (the lowest LCC along with fulfillment of the qualitative criteria).</p><p>The main result is that; it is possible to employ LCCA in the maintenance outsourcing process to achieve a strategic model valid for decisions taking over the life length of the process. Consequently, the main recommendation for the case company is to outsource these activities and to transfer it to ABB service supplier.</p>