Detta examensarbete behandlar hur olika företag reducerar ställtider samt hur de förhåller sig tillvarandra och beskriven teori. Problemområden som detta arbete behandlar är huvudsakligen standardiserad arbetssätt, produktionsplanering samt rengöring och underhåll. Arbetet går främst ut på att analysera tillvägagångssätten, faktorer samt metoder som bidrar till hur företag reducerar ställtider. Med hjälp av semistrukturerade intervjuer med fyra olika företag gjordes en litteraturstudie som stöd till de olika problemområden som företagen brottas med. Genomförande av kodning som går hand i hand med semistrukturerade intervjuer som var till hjälp för att få en tydligare helhetsbild över företagens syn på hur ställtider reduceras men gjorde det även enklare att hitta samband och mönster i förhållande till de problem som bidrar till ställtider. En analys och jämförelse gjordes mellan de fyra olika företagen för att se hur de eliminerar de problem som uppstår i produktionen. Det kunde påvisas att det rådde både likheter och olikheter bland företagen. De främsta likheterna var hur företagen eliminerade problemområden som uppstod. De olikheter som fanns bland de olika företagen kunde knytas till ledningens kunskap om just ställtidsreduktion, det rådde olika kunskapsnivåer. En annat viktig faktor som bidrog till olikheter bland företagen var deras storlek i volym som i sin tur även påverkar produktionsförmågan. / This thesis deals with how different companies reduce downtime and how they relate to each other and described theory. Problem areas that this work deals with are mainly standardized working methods, production planning and cleaning and maintenance. The work is mainly about analyzing approaches, factors and methods that contribute to how companies reduce downtime. With the help of semi-structured interviews with four different companies, a literature study was conducted to support the different problem areas that the companies struggle with. Implementation of coding that goes hand in hand with semi-structured interviews that was helpful in gaining a clearer overall picture of companies' views on how set-up times are reduced, but also made it easier to find connections and patterns in relation to the problems that contribute to set-up times. An analysis and comparison was made between the four different companies to see how they eliminate the problems that arise in production. It could be shown that there were both similarities and differences among the companies. The main similarities were how the companies eliminated problem areas that arose. The differences that existed among the different companies could be linked to the management's knowledge of downtime reduction, there were different levels of knowledge. Another important factor that contributed to differences among companies was their size in volume, which in turn also affects production capacity.

The Phase change materials (PCM) have the ability to absorb and release heat as the temperature changes from high to low temperature and vice versa. The use of phase change materials has increased in the construction sector due to the established environmental requirements and the various application benefits, especially in the thermal comfort of building applications and construction of sustainable infrastructure around the world (Berardi and Gallardo, 2019). Over the past decade, many studies have been conducted on the thermal properties of PCM (phase change material), however, few studies have focused on the study effect of PCM on mechanical and physical properties, although of great importance. In this work, three different microencapsulated types of phase change material (PCM) have been studied, while its effect on the mechanical and hydration properties of the cement paste with regard to constant ratio of water to cement ratio has been taken into account. The PCMs that have been studied are the following: Microencapsulated PCM, which is Nextek 24 D, Nextek 57D (Microtek Laboratories) and Croda Therm ME29P (Croda). In this study, various tests were performed on cementitious paste mixed with different doses of PCM to test the effect that PCM has on the cement hydration (under semi-adiabatic and isothermal conditions), the physical properties (setting time, slump flow, density) and the mechanical properties ( compressive strength). The results of this study indicated that both the melting point of the PCM and its amount have a decisive effect on the properties of the cement paste. Finally, the following conclusions have been drawn: • Additions of different dosage levels of the 24D and Croda PCM types showed that an increase in the dosage resulted in impaired mechanical and physical properties such as compressive strength of the cement paste (mechanical) decreased, and the density and random flow decreased (physical). While Nextek 57D did not show a great effect on cement paste according to density and random flow, which gives reduced negative impact on cement paste workability (physical). According to the mechanical properties, Nextek57D PCM with different levels of levels showed immediate positive effect on cement paste compressive strength compared to reference paste (no addition of PCM), and other cement pastes with other PCM types used in this study. • Mikrotek 57D PCM also gives a positive effect at different dose levels compared to two other types of Nextek 24D and Croda PCM regarding the effect of heat flow, which gives rise to hydration heat during the cement hydration process. However, other types of Nextek 24D and Croda in all quantities showed negligible effect on the heat flow during the cement hydration process.