El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / In this document it was proposed to apply Lean Agriculture, using the five Lean principles focused on the production of organic apples, which would allow to achieve a differentiated product, through the reduction of waste, improvements in the quality of activities and the commitment of the farmers. For this, a review of the literature that corroborated the impact of the methodology was carried out. In addition, surveys were conducted, taking a sample of farmers, which evidenced the gap. Finally it was obtained as a conclusion that after the implementation of the Lean Agriculture methodology in the processes, an increase in production suitable for sale in traditional and organic markets is achieved. In addition, the increase in quality achieved a percent of production suitable for exporting.

Bakgrund: Lean som arbetskoncept är väl definierat. Vanligtvis initieras Lean på ledningsnivån och som sedan rör sig nedåt i den hierarkiska ordningen inom en organisation där samtliga medarbetare involveras. På så vis är målsättningen att bidra till en organisationskultur som har positiv inverkan på organisationens utveckling och produktivitet. Vi vill med denna studie närmare undersöka de praktiska erfarenheterna från en svensk arbetslivsförvaltning i deras arbete med implementering av Lean och dess effekter.  Syfte: Ambitionen med denna studie är att undersöka upplevelser av fördelar och utmaningar av Lean hos chefer och medarbetare. Detta genom att undersöka implementering av Lean i en kommunal arbetslivsförvaltning och dess verksamheter.  Metod: Studien bygger på kvalitativa intervjuer med åtta personer som har haft ansvar för implementering av Lean i en arbetslivsförvaltning. Materialet analyseras med i förväg valda teoretiska utgångspunkter såsom Nyinstitutionell teori och Skandinavisk institutionell teori.  Slutsatser: Implementeringen av Lean upplevs som positivt av respondenterna inom kommunkoncernen utifrån att de söker efter ständiga förbättringar och att det ses som viktigt att testa effektiviseringsmodeller. Implementering av Lean medförde ett annat förhållningssätt gentemot medborgarna som respondenterna möter i sitt arbete. Det är i högre utsträckning medborgaren som är i fokus nu. Medarbetarna upplever att de beaktar medborgarna mer nu än tidigare, då verksamheten präglades av ett myndighetstänk och tidskrävande administrativa processer. Vi har kommit till slutsatsen att Lean ibland används av fel anledning. Medarbetarna upplever inte att Lean ska användas för medarbetarens och medborgarens bästa. Studiens slutsats är att metoden inte bör användas som en effektivisering för att minska kostnader och personal.

Improvements to heritage gas turbine engines will be needed in the coming years as the demand made on these systems increase. While industry continually presses for higher performance of both military and civilian aero engines, the government simultaneously raises the bar for emissions standards in the commercial sector to support public health. The next generation of aerospace gas turbine engines will be defined by their ability to operate at high power conditions while maintaining efficiency. This challenge is compounded by airlines' proposition of a return to supersonic flight- an operating regime characterized by higher total temperatures, and thus more NOx production. Lean Direct Injection (LDI) is a combustion scheme that was proposed by NASA, and inherently addresses the needs of both the private sector and the military. LDI is a liquid fueled combustor that promotes rapid mixing of fuel and air at the entrance of the combustor. Despite the benefits of LDI, it has never been implemented, nor has any other lean burning scheme been implemented in an aircraft due to the system level complications of such technology. This dissertation focuses on the dynamics of thermoacoustic instability and lean blowout (LBO), two of the major complications that industry will face when they attempt to incorporate LDI in a production engine. The present dissertation investigates these dynamics from a fundamental and applications standpoint. Fundamental insights on thermoacoustic instabilities are developed by investigating droplet dynamics in a self-excited flow field, and significant oscillations in droplet diameters are discerned. PDPA measurement will be taken to identify coupling of the fuel spray with the instability, and a phase locking algorithm will be used to develop a new spray parameter than is more indicative of combustion heat release that the standard Sauter mean diameter. Next, while varying the swirl number and the venturi geometry of the combustor, the evolution of the flow field will be characterized. An in-house innovation called the Direct Rotation Swirler (DRS) is built for this purpose. The DRS uses an active geometry to provide continuously variable swirl number modulation. The effects of these changes on lean blow out, pressure drop and NOx emissions will then be experimentally determined. Venturis were rapidly manufactured using a ii casting procedure that was developed to make venturi geometries from a commercially available ceramic at very low cost. / Doctor of Philosophy / Improvements to heritage gas turbine engines will be needed in the coming years as the demand made on these systems increase. While industry continually presses for higher performance of both military and civilian aero engines, the government simultaneously raises the bar for emissions standards in the commercial sector to support public health. The next generation of aerospace gas turbine engines will be defined by their ability to operate at high power conditions while maintaining efficiency. This challenge in compounded by airlines' proposition of a return to supersonic flight- an operating regime characterized by higher total temperatures, and thus more NOx production. Lean Direct Injection (LDI) is a combustion scheme that was proposed by NASA, and inherently addresses the needs of both the private sector and the military. LDI is a liquid fueled combustor that promotes rapid mixing of fuel and air at the entrance of the combustor. Rapid mixing yields a clean, even flame and eliminates the fuel-rich primary zone which is the heart of NOx production. Despite the benefits of LDI, it has never been implemented, nor has any other lean burning scheme been implemented in an aircraft due to the system level complications of such technology. This dissertation focuses on two of the major complications that industry will face when they attempt to incorporate LDI in a production engine. Drastically reducing the local hot spots in the primary zone is fundamentally necessary to improve pattern factor and emissions, but this change is directly at odds with two dynamic phenomenon that plague combustors. These effects are thermoacoustic instabilities, and lean blow out. Thermoacoustic instabilities are a major concern in any type of combustor and instabilities are more common and more intense in lean engines which is a significant safety risk to aircraft. A thermoacoustic instability occurs when pressure waves in an engine grow to high amplitudes. Small pressure waves are normal in any combustion process, but when the acoustic waves couple with the heat release, the waves can grow uncontrollably. The amplitudes can reach magnitudes capable of damaging the combustor or significantly reducing its cyclic life. Due to the high iv standard of safety in the aerospace industry, lean combustion will not be implemented until engines can be designed to avoid instabilities throughout the entire flight envelope. Lean blow out occurs when the fuel to air ratio of the engine becomes too low to sustain a flame. Lean blow out is a transient phenomenon that is dependent on local flame speeds, local chemical time scales and turbulence parameters. Typically, lean blow out is combated by designing a rich flame anchoring region that burns with plenty of excess fuel so that even if the fuel flow rate is reduced, a core region is still within its flammability regions. The present dissertation investigates these dynamics from a fundamental and applications standpoint. Fundamental insights on thermoacoustic instabilities are developed by investigating droplet dynamics in a self-excited flow field, and significant oscillations in droplet diameters are discerned. PDPA measurement will be taken to identify coupling of the fuel spray with the instability, and a phase locking algorithm will be used to develop a new spray parameter than is more indicative of combustion heat release that the standard Sauter mean diameter. Next, while varying the swirl number and the venturi geometry of the combustor, the evolution of the flow field will be characterized. An in-house innovation called the Direct Rotation Swirler (DRS) is built for this purpose. The DRS uses an active geometry to provide continuously variable swirl number modulation. The effects of these changes on lean blow out, pressure drop and NOx emissions will then be experimentally determined. Venturis were rapidly manufactured using a casting procedure that was developed to make venturi geometries from a commercially available ceramic at very low cost.

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Since 1990, the number of travels by train has increased by approximately 75 % in Sweden. The necessity of track maintenance has caught the attention of the Swedishgovernment and during the next few years there will be an increase in maintenance.This forces the train company SJ AB to make changes in their normal train servicesduring these planed track maintenances.This thesis examines the way SJ AB works with adapting their traffic to track workand in particular how information flows in the organisation regarding this, togetherwith how the information is communicated within SJ AB. The objective is to improvethe communication regarding track work but also examine if the concept of Lean canbe implemented in the communication within the organization.This study shows how the process with communication needs to be moretransparent and open. This enables for all involved parties throughout SJ AB to followthe steps in the process and therefore gain awareness of progress and obstacles thatoccur. Three aspects of Lean were discovered from empirical results and representwhere improvement could be made in internal communication. These weretransparency, standards and feedback. Finally, the last part in making thecommunication more effective would be to educate employees in language andrhetoric to make them speak and write in the same language. This would minimize theproblems with interpretation of information regarding track maintenance and makethe communication flow through the organization in an effective way.

The poor safety situation in the United Kingdom (UK) construction industry and its adverse socio-economic record are well documented in the existing literature. The application of Lean Construction techniques has been proposed as an effective strategy to address accidents on construction sites, a major safety concern in the construction industry. However, examination of the relationship between Lean Construction techniques and safety issues has been marginal. This study explores this relationship with the aim of developing a framework for using Lean Construction techniques to promote safety on UK construction sites. A framework was initially devised based on a synthesis of the literature and further refined based on findings from interviews held with 10 Lean Construction practitioners on antecedents of Lean Construction techniques and safety issues. In order to develop and confirm the framework, data was collected from practicing Lean Construction organisations using a questionnaire survey and analysed using descriptive statistics, inferential statistics and inter-rater agreement statistical test to examine the pattern and extent of the relationships. The study found a total of thirty-eight (38) relationships between Lean Construction techniques and safety issues. These relationships are mainly positive in nature in that they demonstrate path to improvement in safety on construction sites. They show which techniques could be used to address the relevant safety issue. Furthermore, it was established that the application of Lean Construction techniques on construction sites can be impeded by challenges such as: lack of Lean Construction knowledge, complexity, misconception about Lean and difficulties in changing employees’ working culture. The study identified strategies that could be used to address these challenges. These include enlightenment on benefits of Lean practice, publication of improvements realised from Lean practice, training, workers’ involvement and empowerment, persistence, robust planning and gradual step-by-step implementation. The study, therefore, concludes that Lean Construction techniques have positive relationships with safety issues on construction sites in the UK and on the basis of the relationships develops an integrated framework to guide application of the techniques by contracting organisations in promoting safety. The study makes a number of recommendations including the incorporation of Lean Construction practice into government health and safety initiatives, regulations and policies, and identifies areas for further research.

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This thesis is a case study conducted at the Torsby hospital, medicine department in Torsby, Sweden. The hospital has some financial, communication, and process standardizing problems and was aiming to solve them by implementing lean strategies. The data for this study were collected through structured interviews and observations in the hospital. A thorough discussion of the information gathered from the interviews and the observations made are presented related to the theoretical frame of the study. The findings of this study showed that the lean concept is actually applicable to the healthcare system except for some problems that may affect the success of the lean implementation process in the hospital. By removing or fixing these problems, the hospital can reap the benefits of the implementation process. This study presents and discusses problems in question and suggests some relevant solutions.