Lightweight cellular concrete (LCC) is mainly a mixture of water, cement, and foam bubbles. LCC generally has a cast density between 20-60 pcf and an air content between 49-84%. LCC is often used as a fill material because it has a low unit weight which reduces settlement. LCC is increasingly being considered as a backfill behind Mechanically Stabilized Earth (MSE) walls and embankments. Although engineers are using LCC in MSE walls or free face walls (MSE wall without the concrete panels or reinforcements), there is presently a lack of information regarding the performance and behavior of LCC to guide them. This research attempts to answer questions on the design of MSE walls backfilled with LCC and free face LCC walls by providing a well-documented case history and evaluating if LCC can be modeled as a c-ϕ material. A steel frame test box (10 ft wide x 12 ft long x 10 ft high) with a MSE wall on one side was constructed for the research. The box was filled with four lifts of LCC with steel ribbed-strip reinforcements extending into the LCC behind the MSE wall panels at the center of each lift. After the LCC was cured, two static load tests were performed by applying a surcharge load to the surface of the LCC. In one test, surcharge pressure was applied adjacent to the MSE wall to produce failure of the wall system. In a second test, the surcharge pressure was placed adjacent to a free face of the LCC to produce failure. String potentiometers (string pots), load cells, pressure plates, and strain gages were used to measure the behavior of the MSE wall and free face wall during testing. These two tests provided a comparison between LCC behavior with a MSE wall relative to a LCC free face. Failure of the free face wall with unreinforced LCC backfill in this test can be predicted using Rankine’s lateral force equation using a c-ϕ model. Failure angle at the base of the free face wall was between 51-63° which corresponds with an average friction angle (ϕ) of 24° and cohesion (c) of 1575 psf with an upper bound ϕ = 34° and a c = 1285 psf. The presence of reinforcements in the LCC backfill behind the MSE wall increased the capacity of the wall to hold a surcharge load. The presence of reinforcements in the LCC behind MSE walls also led to a much more ductile surcharge pressure vs. lateral deflection curve for the MSE wall compared to the free face wall.

La mer joue un rôle essentiel dans la régulation du climat et dans l'équilibre écologique. Les océans et les mers constituent une source de richesse, un immense réservoir de ressources alimentaires et d'emplois pour un grand nombre de personnes. La mer Méditerranée est un écosystème sensible soumis à de fortes pressions par les activités humaines comme la pêche, l'exploration gazière et pétrolière, l'immersion des déchets ou d'autres matières en mer, le transport maritime, le transfert d'espèces aquatiques envahissantes par les eaux de ballast et le tourisme littoral. La France durement touchée par les naufrages de l'Amoco Cadiz, de l'Erika et du Prestige, a pris de nombreuses initiatives tant au niveau international que régional. La complexité du problème de la pollution marine, due à la diversité des facteurs polluants et à leurs sources diffuses, a favorisé une approche sectorielle. Cette approche s'est traduite par l'adoption, aux niveaux national, régional et international, d'un ensemble disparate de politiques, textes législatifs, programmes et plans d'action dans le domaine de la protection du milieu marin. Il s'agit d'un corps de règles étouffées comprenant des mesures préventives et répressives. La complexité institutionnelle et juridique de la protection du milieu marin empêche pourtant la protection effective de la mer. Dans ce contexte, la communauté internationale encourage la mise en œuvre d'une approche écosystématique pour les océans. À l'échelle européenne, l'adoption de la directive-cadre « stratégie pour le milieu marin » favorise la cohérence entre les différentes politiques européennes et l'intégration des préoccupations environnementales dans toutes les politiques liées à la mer. De plus, l'efficacité de la législation européenne dans le domaine de la lutte contre la pollution marine a été renforcée par l'adoption d'un cadre commun de responsabilité pour la prévention et la réparation des préjudices environnementaux. / The sea plays a vital role in regulating climate and in maintaining ecological balance. The oceans and the sea constitute a source of wealth, an immense reservoir of food resources and of employment for many people. The Mediterranean Sea is a sensitive ecosystem, subject to strong pressures derived from human activities, such as fishing, oil and gas exploration, dumping of waste and other matter in the sea, maritime transport, transfer of aquatic invasive species via ballast water and littoral tourism. France, severely affected by the sinking of the Amoco Cadiz, the Erika and the Prestige, took numerous initiatives not only at an international but also at a regional level. The complexity of the marine pollution problem, due to the diversity of polluting factors and to their diffuse sources, has favored a regional approach. This approach has resulted in the adoption, at a national, regional and international level, of a network of policies, legislative texts, programs and action plans in the field of marine environment protection. It constitutes a stifling body of rules, comprising preventive and repressive measures. The institutional and legal complexity of marine protection hinders, however, the effective protection of the marine environment. ln this context, the international community encourages the implementation of an ecosystem approach to oceans. At European level, the adoption of the Framework Directive «Strategy for the Marine Environment» favours a consistency between different EU policies as well as an integration of environmental considerations into ail policies related to the sea. Furthermore, the effectiveness of European legislation in the field of the fight again marine pollution, has been reinforced by the adoption of a common framework of liability with regard to the prevention and remedy of environment damage.

Dagens företag lägger ner allt mer tid och resurser på att utöka variantfloran i deras produktsortiment. Syftet är att nå ut till ett bredare segment av kunder samtidigt som företaget behåller en konkurrenskraftig position på marknaden. Vid framtagning av nya produkter ställs Axis Communications ofta inför utmaningen att ta beslut om att tillverka en eller flera varianter. I dagsläget tas beslut om att tillverka fler varianter i produktsortimentet utifrån priset på direkt material och försäljningsvolymen för varje variant. Axis Communications saknar därmed kunskap om vilka ytterligare faktorer som påverkas när beslut om variantskapande ska tas. Syftet med studien är att ta fram en beräkningsmodell som kan användas som beslutsunderlag vid analys av kostnader i att tillverka mer än en produktvariant. För att besvara syftet har studien genomfört två fallstudier utifrån två olika produkter i Axis Communications produktsortiment. Den första fallstudien analyserar nuläget av tillverkningen hos Axis Communications kontraktstillverkare där kostnader som påverkas av att flera varianter tillverkas identifieras och beräknas. Den andra fallstudien är en fiktivt fallstudie där de identifierade kostnaderna beräknas på nytt men då endast en variant tillverkas och resterande varianter tagits bort. Därefter utfördes en analys på hur de identifierade kostnaderna påverkas vid tillverkning av endast en variant. Utifrån litteraturstudier har de kostnader som påverkas i samband med att flera varianter tillverkas identifierats. Vidare har även processkartläggningar samt ett studiebesök hos en av Axis Communications kontraktstillverkare genomförts där ytterligare relevanta kostnader identifierats och bekräftats av personer med bred kunskap inom området. De kostnader som identifierats i studien och som därmed ansett påverkas mest av att variantfloran förändras är följande: Direkta särkostnader Direkt material Lagerföringskostnader Ställkostnader Fixtur- och verktygskostnader Indirekta särkostnader Kvalitetskostnader Time to Market Investeringskostnader Resurskostnader för utveckling av mekanik Resurskostnader för utvecklig av elektronik Certifieringskostnader Verktygskostnader Kostnader för test av produktion Kostnader för framtagning av prototyper Resultatet för direkt material visade att det går att utgå från ett medelvärde av priset för direkt material samt den prognostiserade försäljningsvolymen per variant för att skapa sig en första uppfattning om hur mycket variantskapande egentligen kostar. Lagerföringskostnaden visade sig också påverkas vid tillverkning av endast en variant. Lagerföringskostnaden minskade i lagret för komponenter men ökade samtidigt i färdigvarulagret eftersom att det endast är den dyrare varianten med avseende på direkt material som tillverkas då det är den variant som har samtliga funktioner jämfört med resterande varianter. Ställkostnaden eliminerades helt då ställtiderna som uppstår vid byte av varianter i tillverkningen försvann. Vidare så halverades kostnaderna för fixturer och verktyg. Kvalitetskostnaden visade sig vara svårare att kvantifiera, dock gick det att inse att desto högre volym som tillverkas av en variant desto fortare når varianten de uppsatta kvalitetsmålen vilket i sin tur bidrar till lägre kvalitetskostnader. Dessutom innebär ett lägre antal varianter i en och samma produktionslina att hanteringen blir lättare då bland annat risken för felmontering minskar. Det blir även lättare att identifiera, prioritera samt åtgärda fel som kan tänkas uppstå i produktionslinan. Det leder i sin tur till att kvalitetskostnaderna minskar. Time to Market påverkades också när endast en variant tillverkades. Även om Time to Market inte direkt kan ses som en kostnad utan snarare som ett intäktsbortfall, påvisade studien att det går fortare att få fram produkterna på marknaden om antalet varianter minskar. Slutligen studerades olika investeringskostnader som går att koppla till tillverkningen av flera varianter och resultatet visade på att det går att minska investeringskostnaderna om endast en variant tillverkas. Utifrån resultatet från de två fallstudierna utformades en beräkningsmodell åt Axis Communications som ska hjälpa företaget med att ta beslut om variantskapande. Beräkningsmodellen lyfter fram de kostnader som påverkas mest av en förändring i variantfloran tillsammans med en beskrivning av hur kostnaderna ska beräknas. Med hjälp av beräkningsmodellen kan Axis Communications beslut om variantskapande underlättas jämfört med hur de tar beslut idag. / Today’s companies spend a significant amount of time and resources on increasing the number of product variants in their product range. The aim is to reach a wider segment of customers while maintaining a competitive position in the market. When developing new products, Axis Communications is often faced with the challenge of deciding whether to focus on one or more product variants. At present, focus is directed towards developing more product variants in the product range based on the price of direct material and the sales volume for each variant. Axis Communications therefore lacks knowledge of what additional factors that are affected when decisions about creating more product variants are taken. The purpose of the study is to provide a calculation model that can be used as a basis for analysing costs in producing more than one product variant. In order to achieve this purpose, the study has carried out two case studies based on two different products in Axis Communications product range. The first case study analyses the current state of production at Axis Communications’ contracted manufacturers, where costs that are affected by the production of multiple variants are identified and calculated. The second case study is a fictitious case study where the identified costs are calculated again, but only when one product variant is manufactured and the remaining product variants are disregarded. This was followed by an analysis regarding how the identified costs are affected when only one product variant is manufactured. Based on literature studies, the costs associated with the production of several variants have been identified. Furthermore, process flow charts have been developed and a study visit to one of Axis Communications contracted manufacturers was undertaken, where additional relevant costs have been identified and confirmed by persons with broad knowledge about the manufacturing processes. The costs identified to be affected the most by the variation of product variants are as follows: Direct incremental costs Direct material Inventory carrying costs Setup costs Fixture- and tooling costs Indirect incremental costs Quality costs Time to Market Investment costs Resource costs for the development of mechanics Resource costs for the development of electronics Certification costs Tooling costs Costs for testing of production Costs for prototyping The result for direct material showed that an average of the price of direct material as well as the forecasted production volume for each product variant can be assumed to create an initial perception of how much an increase of product variants actually costs. The inventory carrying cost also proved affected by the manufacturing of only one product variant. The inventory carrying cost decreased in the inventory of components but increased at the same time in the finished goods inventory since it is only the most expensive product variant with all functions compared to the other product variants that is being stored. The setup cost was eliminated since the setup times that occurred when changing product variants in the production disappeared. Furthermore, the cost of fixtures and tools was halved. The quality cost proved to be harder to quantify, however, it was realized that the higher the volume produced by a product variant the faster the product variant reaches the set quality goals, which in turn contributes to lower quality costs. Additionally, a lower number of product variants in the same production line means that handling becomes easier, including the risk of errors in assembling the product variant. It will also be easier to identify, prioritize and correct errors that may occur in the production line. This in turn leads to a reduction of quality costs. Time to Market was also affected when only one product variant was manufactured. Although Time to Market cannot be seen directly as a cost but rather as a loss of revenue, the study showed that it is faster to launch the product on the market if the number of product variants decreases. Finally, various investment costs were studied that could be linked to the production of several product variants, and the result showed that it is possible to reduce the investment costs if only one product variant is manufactured. Based on the outcome of the two case studies, a calculation model was designed for Axis Communications to help the company decide whether to manufacture product variants or not. The calculation model explains the costs that are affected the most by a change of number of product variants together with a description of how the costs are to be calculated. Using the calculation model will enable Axis Communications to make well-informed decision on whether or not to introduce more product variants in the product range.

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