JPS Teknik AB in Färila, located in the middle of Sweden, is a company in manufacturingsaw units to harvester heads. This thesis is about the company's best selling saw unit, JPSR5500. The saw unit is powered by a hydraulic motor, the torque is transmitted from themotor into the saw unit thought a spline coupling. In this spline coupling, some of the unitshave been weared out after about 2000 harvester machine hours. When the splines wear outthe failure induce a total stop, the bolt connecting the hub and the motor shaft breaks, and thesaw unit assembly get loose. The purpose with this study is to find the root cause of thefailure and the goal is to give suggestions to improve the design to avoid failure. The method used to achieve the purpose is based on Ullman's mechanical design processwhere a root cause analysis is a central part. This analysis is built on two main pillars, aliterature study concerning previous research about wear in spline couplings and a knowledgebased study about the product with a customer focus. A sample of previous research in thistopic is about the load distribution in a spline coupling due to different load cases and angularmisalignment, wear mechanisms and the effect of washers in a pretension bolt joint with adynamic working condition. The main conclusions of this study is that the hydraulic motor axis should be extended. Theoperator's manual and assembly instructions should be updated and revised annually, thecompany should also invest in education and training for the users of the product.

Adaptive video streaming is perpetually influenced by unpredictable network conditions, whichcauses playback interruptions like stalling, rebuffering and video bit rate fluctuations. Thisleads to potential degradation of end-user Quality of Experience (QoE) and may make userchurn from the service. Video QoE modelling that precisely predicts the end users QoE underthese unstable conditions is taken into consideration quickly. The root cause analysis for thesedegradations is required for the service provider. These sudden changes in trend are not visiblefrom monitoring the data from the underlying network service. Thus, this is challenging toknow this change and model the instantaneous QoE. For this modelling continuous time, QoEratings are taken into consideration rather than the overall end QoE rating per video. To reducethe user risk of churning the network providers should give the best quality to the users. In this thesis, we proposed the QoE modelling to analyze the user reactions change over timeusing machine learning models. The machine learning models are used to predict the QoEratings and change patterns in ratings. We test the model on video Quality dataset availablepublicly which contains the user subjective QoE ratings for the network distortions. M5P modeltree algorithm is used for the prediction of user ratings over time. M5P model gives themathematical equations and leads to more insights by given equations. Results of the algorithmshow that model tree is a good approach for the prediction of the continuous QoE and to detectchange points of ratings. It is shown that to which extent these algorithms are used to estimatechanges. The analysis of model provides valuable insights by analyzing exponential transitionsbetween different level of predicted ratings. The outcome provided by the analysis explains theuser behavior when the quality decreases the user ratings decrease faster than the increase inquality with time. The earlier work on the exponential transitions of instantaneous QoE overtime is supported by the model tree to the user reaction to sudden changes such as video freezes.

The operational advantages of a pull system are very well documented. These advantages include not only operational efficiency and quality, but also the enhancement of the customer oriented of the organization. The objective of this field study is to examine the applicability and potential advantages of a pull operational system in a mid-size manufacturing organization. Philosophies, tools, and concepts of Just-in-Time, Theory of Constraints, Business Process Re-engineering, and Root Cause Analysis are used to analyze the existing operational system, to identify its weaknesses, and finally to re-engineer it to be more consistent with a pull operational system. The results of this field study appear to be consistent with reported findings in the literature. The results point to both operational gains and customer related benefits which can be attributed to the pull operational system philosophy. Conclusions and recommendations are presented and discussed in light of their practical and theoretical implications.

Error equivalence concerns the mechanism whereby different error sources result in identical deviation and variation patterns on part features. This could have dual effects on process variation reduction: it significantly increases the complexity of root cause diagnosis in process control, and provides an opportunity to use one error source as based error to compensate the others. There are fruitful research accomplishments on establishing error equivalence methodology, such as error equivalence modeling, and an error compensating error strategy. However, no work has been done on developing an efficient process design approach by investigating error equivalence. Furthermore, besides the process mean shift, process fault also manifests itself as variation increase. In this regard, studying variation equivalence may help to improve the root cause identification approach. This thesis presents engineering driven approaches for process design and control via embedding error equivalence mechanisms to achieve a better, insightful understanding and control of manufacturing processes. The first issue to be studied is manufacturing process design and optimization based on the error equivalence. Using the error prediction model that transforms different types of errors to the equivalent amount of one base error, the research derives a novel process tolerance stackup model allowing tolerance synthesis to be conducted. Design of computer experiments is introduced to assist the process design optimization. Secondly, diagnosis of multiple variation sources under error equivalence is conducted. This allows for exploration and study of the possible equivalent variation patterns among multiple error sources and the construction of the library of equivalent covariance matrices. Based on the equivalent variation patterns library, this thesis presents an excitation-response path orientation approach to improve the process variation sources identification under variation equivalence. The results show that error equivalence mechanism can significantly reduce design space and release us from considerable symbol computation load, thus improve process design. Moreover, by studying the variation equivalence mechanism, we can improve the process diagnosis and root cause identification.

När Scanias maskiner som ska testa nya lastbilskomponenter eller hela lastbilar, så kallade testriggar, inte fungerar som de ska så fanns det i dagsläget en uppfattning att problemen i vissa fall dels var återkommande och dels var svåranalyserade. På grund av detta ville Scania Tekniskt Centrum (STC) införa rotorsaksanalyser av när testriggar inte fungerade som de skulle. Denna studie har undersökt vad som i dagsläget behövde förändras och vad som möjliggjorde att rotorsaksanalyser av fallerande hos testriggarna skulle fungera så bra som möjligt. En nulägesanalys gjordes. Resultaten av denna visade på att fyra roller fanns som var involverade i att åtgärda fel hos testriggarna, nämligen de som äger riggarna, de som arbetar med underhåll av riggarna, de som utvecklar riggarna och de som är ansvariga för arbetsmiljön och säkerheten hos riggarna. En process map skapades för att visa hur dessa roller i dagsläget samverkade för att bygga testriggar och åtgärda fel hos dem. Resultaten av nulägesanalysen visade på att fyra övergripande faktorer påverkade huruvida rotorsaksanalyser skulle kunna genomföras. Den första var att ha ett väldefinierat standardförfarande att följa. Den andra var att det fanns en kultur som tillät att utföra rotorsaksanalyser. Den tredje var att bakgrundskunskap kring ett fel skulle finnas tillgänglig. Den fjärde var att kunna sammansätta grupper av olika typer av roller som skulle kunna samarbeta. Dessa fyra faktorer var de som utgicks ifrån för att redovisa saker som fungerade väl och saker som krävde förändring för att rotorsaksanalyser skulle fungera på bästa sätt. Utöver detta gavs förslag på förändringar som skulle åtgärda saker som förhindrade rotorsaksanalyser.

Due to uncertainty in manufacturing processes, applied probability and statistics have been widely applied for quality and productivity improvement. In spite of significant achievements made in causality modeling for control of process variations, there exists a lack of understanding on error equivalence phenomenon, which concerns the mechanism that different error sources result in identical variation patterns on part features. This so called error equivalence phenomenon could have dual effects on dimensional control: significantly increasing the complexity of root cause identification, and providing an opportunity to use one error source to counteract or compensate the others. Most of previous research has focused on analyses of individual errors, process modeling of variation propagation, process diagnosis, reduction of sensing noise, and error compensation for machine tool. This dissertation presents a mathematical formulation of the error equivalence to achieve a better, insightful understanding, and control of manufacturing process. The first issue to be studied is mathematical modeling of the error equivalence phenomenon in manufacturing to predict product variation. Using kinematic analysis and analytical geometry, the research derives an error equivalence model that can transform different types of errors to the equivalent amount of one base error. A causal process model is then developed to predict the joint impact of multiple process errors on product features. Second, error equivalence analysis is conducted for root cause identification. Based on the error equivalence modeling, this study proposes a sequential root cause identification procedure to detect and pinpoint the error sources. Comparing with the conventional measurement strategy, the proposed sequential procedure identifies the potential error sources more effectively. Finally, an error-canceling-error compensation strategy with integration of statistical quality control is proposed. A novel error compensation approach has been proposed to compensate for process errors by controlling the base error. The adjustment process and product quality will be monitored by quality control charts. Based on the monitoring results, an updating scheme is developed to enhance the stability and sensitivity of the compensation algorithm. These aspects constitute the "Error Equivalence Theory". The research will lead to new analytical tools and algorithms for continuous variation reduction and quality improvement in manufacturing.

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abstract: A core reform area of President Obama’s Race to the Top (RTT) framework, the Statewide Longitudinal Data Systems (SLDS) program, offered funding to states for the development of their own data systems. As a result, Arizona received funding to build a longitudinal student data system. However the targeted audience—teachers—needed training to move from a state of ‘data rich but information poor’ to one of developing actionable knowledge. In this mixed methods action research study, six teachers from three schools participated in job-embedded data-informed decision making (DIDM) and root cause analysis (RCA) professional development to improve their abilities to employ DIDM and RCA strategies to determine root causes for student achievement gaps. This study was based on the theories of situated learning, specifically the concept of communities of practice (CoP), change theory, and the Concerns-Based Adoption Model (CBAM). Because teachers comprise most of the workforce in a district, it is important to encourage them to shift from working in isolation to effectively implement and sustain changes in practice. To address this concern, an online wiki provided an avenue for participants to interact, reflect, and share experiences across schools as they engaged in the application of new learning. The results from this ten-week study indicated an increase in participant readiness levels to: (a) use and manage data sources, (b) apply strategies, and (c) collaborate with others to solve problems of practice. Results also showed that participants engaged in collaborative conversation using the online wiki when they wanted to share concerns or gain further information to make decisions. The online collaboration results indicated higher levels of online discussion occurred when participants were attempting to solve a problem of practice during the learning process. Overall, participants (a) used collaborative strategies to seek, create, and/or utilize multiple sources of data, not just student learning data, (b) worked through implementation challenges when making changes in practice, and (c) sought further types of data collection to inform their decisions about root causes. Implications from this study warrant further investigation into the use of an online CoP as an avenue for increasing teacher collaboration across schools. / Dissertation/Thesis / Doctoral Dissertation Leadership and Innovation 2016

Through identifying failure manufacturing companies compete in today’s world to gain beneficial attributes. The purpose if this thesis is to develop a model towards identifying failure and the root cause. The model developed to identify failure and the root cause toward it, which should result it decrease in failure time (nonfunction machine). The developed model has tested and analyzed in a manufacturing company. The model has been established through studies based on preventive and predictive maintenance: FMEA & RCA.

The essence of this diploma thesis is the implementation of the analysis and evaluation of the complaint process of chosen organizations in the automotive industry. Using quality control and improvement tools, root causes of ineffectiveness of the process and the high number of customer complaints are identified. Diploma thesis provides a designed method of implementation of quality control and improvement tools in practice. This designed method is aplicable to reduce the overall number of complaints through the identification and elimination of the root causes of complaints related to selected manufacturing process of organization.