<p>Intresset för biobränsleproducerad energi har ökat i takt med att kunderna blivit mer miljömedvetna. På grund av detta har efterfrågan på briketter ökat samtidigt som träindustrin har haft det svårt i en sviktande konjunktur. Därför har ett examensarbete utförts i samarbete med E.ON Värme Sverige AB där undersökningar på bränslebyte i pannor avsedda för torra bränslen till fuktigare, stamvedflis har utfört.<strong></strong></p><p>För denna undersökning har begränsningar införts på övre och undre effekt i form av uppehållstid och slutförbränningstemperatur. Intervallen är enbart beräknade på stamvedflis med 30 och 40 % fukthalt.</p><p>Undersökning visar att det går bra att elda stamvedsflis i briketteldade pannor utan att emissionerna ökar så pass mycket att villkoren för anläggningarna överskrids om lasten hålls inom vissa intervall. Det möjliga effektintervallet ökar med minskad fukthalt på bränslet.</p><p>Undersökningen har visat att det är bränslets kvalitet som är den mest begränsande faktorn.</p> / <p>The interest in bioenergy has increased with increased environmental awareness. The increasing demand on biofuels and the decreasing availability of the rawmaterials for making refined biofuels such as wood briquettes and wood pellets have caused the prices of these biofuels to increase. This report is performed in collaboration with E.ON Värme Sverige AB and its purpose is to investigate the possibilities for a change of fuels in existing boilers designed for refined biofuels, from wood briquettes to wood chips.</p><p>To be able to calculate a power interval where it would be possible to use wood chips with moisture contents of 30 and 40% by weight respectively, we had to make some assumptions regarding maximum flue gas flow, minimum retention time and the lowest temperature regarding complete combustion of CO.</p><p>Our calculations show that it is possible to use woodchips with a moisture content of 30 % w/w without any significant problems in all our boilers. When the moisture content is increased to 40 % w/w the interval for possible power output becomes more narrow. The amount of dust that is being emitted from the boilers does not exceed the limits regulated by environmental law, unless the thermal load of the boiler is too high.</p><p>The single most important factor for a successful change of fuel from wood briquettes to woodchips is that the fuel quality is good.<strong></strong></p>

Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation processes. Design automation is a powerful tool to increase efficiency in these two processes. The benefits of automating the manufacturability analysis process, a part of the production preparation process, are shortened lead-time, improved product performance, quality assurance, and, ultimately, decreased costs. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in a few or in a single step. During the automation process, knowledge about the manufacturability analysis process is collected and stored in central systems, thus allowing full control over the design of production equipments. Topics addressed in this thesis include the flexibility of design automation systems, knowledge-bases containing alternative design rules, the automation of the finite element analysis process, manufacturability analysis over several productions steps, and the determination of production limits by looping the automated manufacturability analysis process. These topics are discussed in connection with the rotary draw bending of aluminum profiles. It is concluded that the concept of design automation can be applied to the manufacturability analysis process at different levels of automation depending on the characteristics of the implemented knowledge. The concept of object orientation should be adapted when implementing a knowledge-base and when developing the geometrical representations of the products. This makes a design automation system flexible enough to edit underlying knowledge and to extend the targeted design space. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent, enabling the design automation system to evaluate its own design proposals. It is also possible to enable such systems to consider sequences of manufacturing steps and loop them to develop decision support guiding engineers early in the design process, saving time and money while still assuring high product quality.

<p>The purpose of this study is to survey and evaluate if the individual contrast sensitivity and preferences for horizontal and vertical lighting level correspond to the values that standard SS-EN 12464-1 recommends for the workplace- and surrounding light levels.</p><p>This study examines if lighting should be adapted after the individuals’ need or if a general value can be found that will cover every individuals’ need for a workplace and surrounding light level. This study also examines if parameters like sex, age and/or glasses/lenses have an effect on the amount of lighting that the test subjects need. Lastly we compared the values concerning the relationship between workplace- and surrounding light levels with standard SS-EN 12464-1’s recommendations.</p><p>The study is carried out with an experimental design that surveys 220 test subjects who were chosen by a selection of convenience. The test subjects did perform a test where they estimated their individual need for lighting in office environments regarding lighting for workplace and its surroundings. Every test subject carried out the test where they repeated the same attempt three times, to establish if the individual lighting need oscillated or if it was constant, whereupon the results were analyzed, compiled and compared to standard SS-EN 12464-1.</p><p>The results show that the minim- and maxim value for the test subjects is between 70 – 4300 lux. The result varies with different parameters such as sex, age and glasses/lenses. We could also state that the relationship between workplace- and surrounding light levels is slightly higher than what standard SS-EN 12464-1 recommends, which should be taken into consideration when planning future lighting constructions.</p><p>Based on the results in this study, our conclusion is that standard SS-EN 12464-1 does not cover the needs on the comfort levels that the test subjects indicated. The values that the test subjects indicated differ from the values that standard SS-EN 12464-1 recommends.</p><p>Since there is a huge spread of the experienced need for lighting between individuals and age groups, we draw the conclusion that general values of measure can’t be applied as a standard on neither workplace- nor surrounding light levels. To fulfill the needs that users have, the lighting construction should be adapted for the individual and give a lighting flood that will fill the individual needs for workplace lighting.</p>

<p>Sammanfattning</p><p>Segerström Automotive tillverkar plåtkomponenter till kunder som Scania, Stiga och Volvo. Företaget befinner sig i en expansiv fas, men konkurrensen på marknaden är hård och kraven på god kvalitet höga. Företaget är kvalitets- och miljöcertifierat. Som del i förbättrings- och kvalitetsarbetet har en nystart av verksamhetens produktionssystem, SAPS (Segerström Automotive Production System), skett. Ett av företagets mål för de närmsta åren är att minska antalet externa reklamationer. Eftersom detta inte skett i önskad takt ansågs en utredning över vad som orsakat antalet reklamationer nödvändig. Examensarbetet har således inriktats mot att göra en nulägesanalys av kvalitetsarbetet inom verksamheten, med utgångspunkt i reklamationshanteringen, samt att påvisa eventuella förbättringsområden. Både kvalitativa och kvantitativa metoder har använts; så som intervjuer, insamling av sekundär och primärdata samt observationer. Teoridelens tyngdpunkt ligger i teorier inom lean production och Total Quality Management.</p><p>En avvikelse uppstår när en produkt ej uppfyller kundens behov. En reklamation är ett sätt att kommunicera en avvikelse. De externa reklamationerna mot Segerström visade sig ofta vara symtom på interna avvikelser. Då det idag saknas ett system för interna reklamationer fångas dessa inte alltid upp. Ofta saknas tid och resurser för att genomföra en djupare orsaksanalys och vidta åtgärder. Felkällan elimineras inte alltid och samma fel återkommer. Delar av den upplevda resursbristen skulle kunna lösas genom en organisatorisk förändring, där tydliga roller för förbättrings- och kvalitetsarbete inom produktionen tas fram.</p><p>Företaget har redan en mängd olika dokument och metoder för kvalitets- och förbättringsarbete, men dessa tycks inte ha förankrats i verksamheten i tillräcklig utsträckning. Utmaningen för företaget är att välja vilka dokument och metoder som skall användas samt att sedan förverkliga dessa. Rutiner bör skapas för att knyta ihop de olika delarna, metoderna och dokumenten. Att standardisera och dokumentera fler av de repetitiva aktiviteterna, identifiera interna kunder, analysera vart i kedjan detaljer bör mätas, etablera kommunikationsforum, utse kvalitetsansvariga i produktionen, utbilda personal inom kvalitetsområdet, ta fram belöningssystem, knyta kostnader direkt till kvalitetsrelaterade ärenden samt att analysera hur information om kvalitet kan samlas in och spridas till berörd personal är områden som företaget rekommenderas att titta närmare på.</p><p>Viktigt är att ledningen ger nödvändiga resurser, skapar en struktur att utgå ifrån samt följer upp kvalitetsarbetet. För att lyckas måste kvalitet bli en prioriterad fråga i hela verksamheten.</p> / <p>Abstract</p><p>Segerström Automotive manufacture sheet metal components to customers like Scania, Stiga and Volvo. The company is expanding, but the competitiveness and the quality requirements on the market are high. The company is quality certified. As part of the work with quality and improvements Segerström Automotive Production System, SAPS, was restarted during the spring 2007. One of the goals for the organization is to decrease the number of external reclamations. To be able to reach the goal a study of what have caused the stagnation of the number of reclamations towards the company was considered as necessary. Thus the thesis has been focused on analyzing the quality work within the organization, with its core in the reclamation handling. Areas for improvements have also been discussed. Both qualitative and quantitative methods have been used; for example interviews, data gathering and observations. The main theories used come from lean production and Total Quality Management.</p><p>A deviation occurs when a product does not meet the customer requirements. Reclamations communicate a deviation. It was found that the external reclamations towards Segerström often were symptoms of internal deviations. Because there is no system for internal reclamations the deviations that are found internally rarely lead to any actions. There is often a lack of time and resources dedicated to analyze the root cause and to take necessary actions to eliminate them; the failure modes are repeated. Parts of the lack of resources could be solved by an organizational change, where clear roles and responsibilities within the fields of quality and improvements were specified.</p><p>The company already has a number of different documents and methods to work with quality and improvements, but those are not implemented and used in a necessary extent. The challenge for Segerström is to choose which documents and methods to use and how to implement them. Routines should be created to link the different parts, methods and documents. To standardize and document more of the repetitive activities, identify internal customers, analyze where in the chain details should be measured, establish channels for communication, have quality responsible persons at the work stations in the production, educate the personnel in quality, create a system for recognition and rewards, document costs of quality and analyze how to gather and spread information about quality to the personnel are areas as the company should look closer into.</p><p>It is important that the leaders of the company give the resources necessary, builds a structure to work from and follow up the work. To succeed quality has to be prioritized within the whole organization.</p>

<p>The goal of this project was to evaluate three main proposals, by the Property Management Department (PMD) of St. Louis County, which the department hoped would reduce energy consumption at their Duluth Jail facility. This particular facility was opened in 1995 and houses approximately 170 inmates. Despite its relatively new construction, the building produces some of the highest utility bills of all of the County’s buildings.</p><p>The proposals put forth by the PMD were the following: to reduce natural gas consumption by using solar water heating for the domestic hot water; to reduce heating and cooling costs by enclosing a light well which is currently open to the sky with a transparent, insulated roof; and to utilize a white roof to reduce cooling demand during the summertime.</p><p>The solar water heating proposal was evaluated by determining the energy the solar system could provide annually and comparing these energy- and monetary savings to the cost of the system. Two solar options were evaluated; one system with 20 collectors and another with 50. Both systems also included condensing boilers to provide supplementary heating during times of low solar output. The annual savings of the 20- and 50 collector systems were 128 and 173 MWh, respectively. This led to a payback period of approximately 17 years for the 20 collector system and 16 years for the 50 collector system.</p><p>Enclosing the open light well, which is an open area inside the perimeter of the building which is designed to give rooms on the inside of the building natural daylight, was evaluated by performing an energy flow analysis comparing the existing condition with one in which a roof topped the well. This involved calculating the U-values of the walls before the skyroof and then using heating and cooling degree days to determine the heat flows through the walls. The enclosed light well was evaluated by performing an energy balance on the well to determine the temperature of the enclosed well. This temperature could then be used to calculate the heat flow through the enclosed light well’s walls. The difference in these heat flows between the two options was then converted to an economic cost to evaluate a payback period. Two grades of Kalwall-brand insulation were evaluated; the “Nanogel” grade and a mid-range grade. The Nanogel-enclosed light well reduced the heating demand by 16 MWh but increased the cooling load by 9 MWh, while the mid-grade enclosed well decreased the heating load by 11 MWh but increased the cooling load by 4 MWh. These added up to net annual savings of $650 for the Nanogel roof and $470 for the mid-grade skyroof. However, the investment costs were so high that the payback periods were between 450 and 550 years.</p><p>Two white roofing options were considered and corresponded to a newly installed roof and one that had weathered for 3 years, thereby reducing its reflectivity. These options were evaluated by determining the mean monthly roof temperatures throughout a typical year and calculating the heat flows through the roofs based on these temperatures. The temperatures were determined by performing a heat balance on the roofs’ surfaces and considering the solar radiation incident on the roofs. The heat flows with the existing black colored roof and the proposed white roofs were thencompared and converted into heating and cooling costs. The white roofs led to summertime air-conditioning savings but created more wintertime heat losses and therefore caused net annual energy cost increases of $560 and $240 for the new and weathered roofs, respectively.</p><p>The recommendations therefore were to implement the solar thermal system but not the other two proposals. Other areas which might benefit from additional investigations include lighting efficiency improvements, water use reductions, and replacement of the existing boilers with either more efficient natural gas units or wood-pellet/biomass boilers.</p>

The purpose of this study is to survey and evaluate if the individual contrast sensitivity and preferences for horizontal and vertical lighting level correspond to the values that standard SS-EN 12464-1 recommends for the workplace- and surrounding light levels. This study examines if lighting should be adapted after the individuals’ need or if a general value can be found that will cover every individuals’ need for a workplace and surrounding light level. This study also examines if parameters like sex, age and/or glasses/lenses have an effect on the amount of lighting that the test subjects need. Lastly we compared the values concerning the relationship between workplace- and surrounding light levels with standard SS-EN 12464-1’s recommendations. The study is carried out with an experimental design that surveys 220 test subjects who were chosen by a selection of convenience. The test subjects did perform a test where they estimated their individual need for lighting in office environments regarding lighting for workplace and its surroundings. Every test subject carried out the test where they repeated the same attempt three times, to establish if the individual lighting need oscillated or if it was constant, whereupon the results were analyzed, compiled and compared to standard SS-EN 12464-1. The results show that the minim- and maxim value for the test subjects is between 70 – 4300 lux. The result varies with different parameters such as sex, age and glasses/lenses. We could also state that the relationship between workplace- and surrounding light levels is slightly higher than what standard SS-EN 12464-1 recommends, which should be taken into consideration when planning future lighting constructions. Based on the results in this study, our conclusion is that standard SS-EN 12464-1 does not cover the needs on the comfort levels that the test subjects indicated. The values that the test subjects indicated differ from the values that standard SS-EN 12464-1 recommends. Since there is a huge spread of the experienced need for lighting between individuals and age groups, we draw the conclusion that general values of measure can’t be applied as a standard on neither workplace- nor surrounding light levels. To fulfill the needs that users have, the lighting construction should be adapted for the individual and give a lighting flood that will fill the individual needs for workplace lighting.

The goal of this project was to evaluate three main proposals, by the Property Management Department (PMD) of St. Louis County, which the department hoped would reduce energy consumption at their Duluth Jail facility. This particular facility was opened in 1995 and houses approximately 170 inmates. Despite its relatively new construction, the building produces some of the highest utility bills of all of the County’s buildings. The proposals put forth by the PMD were the following: to reduce natural gas consumption by using solar water heating for the domestic hot water; to reduce heating and cooling costs by enclosing a light well which is currently open to the sky with a transparent, insulated roof; and to utilize a white roof to reduce cooling demand during the summertime. The solar water heating proposal was evaluated by determining the energy the solar system could provide annually and comparing these energy- and monetary savings to the cost of the system. Two solar options were evaluated; one system with 20 collectors and another with 50. Both systems also included condensing boilers to provide supplementary heating during times of low solar output. The annual savings of the 20- and 50 collector systems were 128 and 173 MWh, respectively. This led to a payback period of approximately 17 years for the 20 collector system and 16 years for the 50 collector system. Enclosing the open light well, which is an open area inside the perimeter of the building which is designed to give rooms on the inside of the building natural daylight, was evaluated by performing an energy flow analysis comparing the existing condition with one in which a roof topped the well. This involved calculating the U-values of the walls before the skyroof and then using heating and cooling degree days to determine the heat flows through the walls. The enclosed light well was evaluated by performing an energy balance on the well to determine the temperature of the enclosed well. This temperature could then be used to calculate the heat flow through the enclosed light well’s walls. The difference in these heat flows between the two options was then converted to an economic cost to evaluate a payback period. Two grades of Kalwall-brand insulation were evaluated; the “Nanogel” grade and a mid-range grade. The Nanogel-enclosed light well reduced the heating demand by 16 MWh but increased the cooling load by 9 MWh, while the mid-grade enclosed well decreased the heating load by 11 MWh but increased the cooling load by 4 MWh. These added up to net annual savings of $650 for the Nanogel roof and $470 for the mid-grade skyroof. However, the investment costs were so high that the payback periods were between 450 and 550 years. Two white roofing options were considered and corresponded to a newly installed roof and one that had weathered for 3 years, thereby reducing its reflectivity. These options were evaluated by determining the mean monthly roof temperatures throughout a typical year and calculating the heat flows through the roofs based on these temperatures. The temperatures were determined by performing a heat balance on the roofs’ surfaces and considering the solar radiation incident on the roofs. The heat flows with the existing black colored roof and the proposed white roofs were thencompared and converted into heating and cooling costs. The white roofs led to summertime air-conditioning savings but created more wintertime heat losses and therefore caused net annual energy cost increases of $560 and $240 for the new and weathered roofs, respectively. The recommendations therefore were to implement the solar thermal system but not the other two proposals. Other areas which might benefit from additional investigations include lighting efficiency improvements, water use reductions, and replacement of the existing boilers with either more efficient natural gas units or wood-pellet/biomass boilers.

Sammanfattning Segerström Automotive tillverkar plåtkomponenter till kunder som Scania, Stiga och Volvo. Företaget befinner sig i en expansiv fas, men konkurrensen på marknaden är hård och kraven på god kvalitet höga. Företaget är kvalitets- och miljöcertifierat. Som del i förbättrings- och kvalitetsarbetet har en nystart av verksamhetens produktionssystem, SAPS (Segerström Automotive Production System), skett. Ett av företagets mål för de närmsta åren är att minska antalet externa reklamationer. Eftersom detta inte skett i önskad takt ansågs en utredning över vad som orsakat antalet reklamationer nödvändig. Examensarbetet har således inriktats mot att göra en nulägesanalys av kvalitetsarbetet inom verksamheten, med utgångspunkt i reklamationshanteringen, samt att påvisa eventuella förbättringsområden. Både kvalitativa och kvantitativa metoder har använts; så som intervjuer, insamling av sekundär och primärdata samt observationer. Teoridelens tyngdpunkt ligger i teorier inom lean production och Total Quality Management. En avvikelse uppstår när en produkt ej uppfyller kundens behov. En reklamation är ett sätt att kommunicera en avvikelse. De externa reklamationerna mot Segerström visade sig ofta vara symtom på interna avvikelser. Då det idag saknas ett system för interna reklamationer fångas dessa inte alltid upp. Ofta saknas tid och resurser för att genomföra en djupare orsaksanalys och vidta åtgärder. Felkällan elimineras inte alltid och samma fel återkommer. Delar av den upplevda resursbristen skulle kunna lösas genom en organisatorisk förändring, där tydliga roller för förbättrings- och kvalitetsarbete inom produktionen tas fram. Företaget har redan en mängd olika dokument och metoder för kvalitets- och förbättringsarbete, men dessa tycks inte ha förankrats i verksamheten i tillräcklig utsträckning. Utmaningen för företaget är att välja vilka dokument och metoder som skall användas samt att sedan förverkliga dessa. Rutiner bör skapas för att knyta ihop de olika delarna, metoderna och dokumenten. Att standardisera och dokumentera fler av de repetitiva aktiviteterna, identifiera interna kunder, analysera vart i kedjan detaljer bör mätas, etablera kommunikationsforum, utse kvalitetsansvariga i produktionen, utbilda personal inom kvalitetsområdet, ta fram belöningssystem, knyta kostnader direkt till kvalitetsrelaterade ärenden samt att analysera hur information om kvalitet kan samlas in och spridas till berörd personal är områden som företaget rekommenderas att titta närmare på. Viktigt är att ledningen ger nödvändiga resurser, skapar en struktur att utgå ifrån samt följer upp kvalitetsarbetet. För att lyckas måste kvalitet bli en prioriterad fråga i hela verksamheten. / Abstract Segerström Automotive manufacture sheet metal components to customers like Scania, Stiga and Volvo. The company is expanding, but the competitiveness and the quality requirements on the market are high. The company is quality certified. As part of the work with quality and improvements Segerström Automotive Production System, SAPS, was restarted during the spring 2007. One of the goals for the organization is to decrease the number of external reclamations. To be able to reach the goal a study of what have caused the stagnation of the number of reclamations towards the company was considered as necessary. Thus the thesis has been focused on analyzing the quality work within the organization, with its core in the reclamation handling. Areas for improvements have also been discussed. Both qualitative and quantitative methods have been used; for example interviews, data gathering and observations. The main theories used come from lean production and Total Quality Management. A deviation occurs when a product does not meet the customer requirements. Reclamations communicate a deviation. It was found that the external reclamations towards Segerström often were symptoms of internal deviations. Because there is no system for internal reclamations the deviations that are found internally rarely lead to any actions. There is often a lack of time and resources dedicated to analyze the root cause and to take necessary actions to eliminate them; the failure modes are repeated. Parts of the lack of resources could be solved by an organizational change, where clear roles and responsibilities within the fields of quality and improvements were specified. The company already has a number of different documents and methods to work with quality and improvements, but those are not implemented and used in a necessary extent. The challenge for Segerström is to choose which documents and methods to use and how to implement them. Routines should be created to link the different parts, methods and documents. To standardize and document more of the repetitive activities, identify internal customers, analyze where in the chain details should be measured, establish channels for communication, have quality responsible persons at the work stations in the production, educate the personnel in quality, create a system for recognition and rewards, document costs of quality and analyze how to gather and spread information about quality to the personnel are areas as the company should look closer into. It is important that the leaders of the company give the resources necessary, builds a structure to work from and follow up the work. To succeed quality has to be prioritized within the whole organization.

Volvo Powertrain, VPT, i Köping tillverkar idag växellådor för tunga fordon. Till medeltunga fordon köper Volvo växellådor från bland annat underleverantören ZF. Volvo vill undersöka scenariot att ta fram AMT - växellådor för medeltunga fordon. I-shift modellen AT2412, som är dimensionerad för en max belastning på 2400 Nm och anpassad för tunga lastbilar, skulle kunna fungera även i medeltunga fordon men är då överdimensionerad och onödigt tung. Med tanke på kommande utvecklingsprojekt behöver Volvo öka sin kunskap hur val av tillverkningsmetoder påverkar vikt och tillverkningskostnader. Det behövs för att öka förståelsen för hur olika prioriteringar ska göras med avseende på vikt och tillverkningskostnader. Examensarbetets syfte var att ge denna förståelse för hur olika tillverkningsprocesser påverkar en transmissions utformning med avseende på mått och vikt utifrån ett givet momentområde. Målet med examensarbetet var att påvisa samband mellan valet av tillverkningsmetoder för enskilda artiklar och hur mycket det kan påverka den kompletta transmissionens vikt samt tillverkningskostnad. Arbetet var avgränsat till att analysera modifierade kugghjul i baslådan. Första delen av arbetet bestod av att dimensionera nya kugghjul anpassade för max belastning på 1600 Nm, detta utifrån samma produktionsupplägg som för befintliga kugghjul som återfinns i bland annat AT2412. Den andra delen bestod av att ta fram faktorer för hur olika tillverkningsmetoder påverkar dimensioneringen och för varje enskilt kugghjul beräkna vikt och tillverkningskostnad då åtta kombinationer av tillverkningsmetoder används. Avslutningsvis gjordes en summering för att visa vilka varianter som ger en optimal växellåda utifrån minimal vikt respektive minimal tillverkningskostnad. Resultatet visar att valet av tillverkningsmetoder leder till att vikten på kugghjulen kan reduceras mer eller mindre. Generellt visar beräkningarna att kugghjul som slipas, kulpenas och manganfosfateras får lägst vikt och blir dyrast att producera. Lägsta tillverkningskostnad uppnås genom att vissa tillverkningsprocesser som kulpening och manganfosfatering utesluts men detta måste då kompenseras med ökad kuggbredd vilket leder till högre vikt. Om VPT väljer att ta fram en ny variant av I-shift där kugghjulen är dimensionerade för 1600Nm så kan växellådan göras 6-11 kg lättare och tillverkningskostnaderna för kugghjulen kan minska med ca 10 procent. / Volvo Powertrain, VPT, in Köping currently manufactures transmissions for heavy-duty vehicles. For medium-duty vehicles Volvo purchase transmissions from their parts supplier ZF. Volvo wants to investigate the scenario to develop AMT - gearboxes for medium-duty vehicles. The I-shift model AT2412, which is designed for a maximum load of 2400 Nm and adapted for heavy-duty vehicles, would be able to function even in the medium-duty vehicles, but would be oversized and excessively heavy. In view of future development Volvo need to increase their knowledge in how the choices of manufacturing methods affect the mass and the manufacturing costs. They need to increase the understanding to make the optimal priorities with respect to mass and manufacturing costs. This study aimed to provide this understanding of how different processes affect a transmission design with respect to mass and measures from a given torque range. The aim of the study was to demonstrate the influence of the choice of production methods for individual items and how much it can affect the complete transmission's mass and manufacturing cost. The work was limited to analyzing the modified gears in the base unit. The first part of the work consisted of designing new gears designed for a maximum load of 1600 Nm, based on the same list of operations as the existing gears, which are found in AT2412. The second part consisted of revealing the factors for the different processes affecting the design regarding to fatigue and structural strength. For eight combinations of manufacturing processes the mass and manufacturing cost was calculated for each gear. Finally, a summary was made to show which combination of manufacturing methods that would give the optimum transmission based on minimum mass and minimum manufacturing cost. The results show that the choice of production methods leads to more or less reduction of mass of the gears. Generally, the calculations show that the gear that is ground, shootpeened and manganese phosphated get the lowest mass and become the most expensive to produce. On the other hand, lower manufacturing cost can be achieved by excluding certain manufacturing operations as shootpeening and manganese phosphate, but this must be compensated by increased facewidth of the gear, leading to increased mass. If VPT decide to develop a new variant of the I-shift in which the gears are designed for 1600Nm then the gearbox can be 6-11 kg lighter and the manufacturing costs of the gears can be reduced by about 10 percent.