Thesis PlanB (M.S.)--University of Wisconsin--Stout, 2006. / Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Stadium driver i dagsläget en centrallagerlösning i Norrköping sedan år 2006. Det har skett en stabil ökning av både butiker samt omsättning sedan bolaget startades. Stadium har ett avtal med PostNord angående driften av lagerverksamheten på centrallagret samt Pema angående bemanningen. Bolagets ökning av butiker har lett till att de nått en väldigt hög nivå i beläggning i centrallagret och därför behövdes en genomlysning av centrallagrets plockprocesser ske. Ett beslutsunderlag har tagits fram för att hjälpa Stadiumlagret med sin frekvensläggning av orderplocket. Två olika plockprocesser har jämförts med varandra, Banan och ett plocktorg. Banan är en automatiserad bana där plocklådor med ordrar transporteras längs Banans olika plockzoner, medan plocktorget är en tom yta där pallar med artiklar placeras och sedan plockas. Tidsstudier och observationer genomfördes på både Banan och plocktorget och dess olika steg i processerna, för att se vilken som var mest tidseffektiv. Kriterier och variabler togs fram för att kunna avgöra vad det är som påverkar respektive plockprocess. Beräkningar utformades för att göra Banans och plocktorgets tider jämförbara. Den plockprocess som sedan tog minst tid totalt skulle vara den bästa plockprocessen att plocka i. För att utforma ett beslutsunderlag som enkelt skulle illustrera ifall skor skulle plockas på plocktorget eller Banan, gjorde valet att utforma beslutsunderlaget i en matris. I matrisen illustreras vid vilket antal artiklar en brytpunkt finns där det skulle vara bättre att plocka på plocktorg. För att undersöka ifall centrallagret någon gång kom upp i de kvantiteter som krävdes för att nå brytpunkten användes verkliga exempel. En känslighetsanalys genomfördes där data från verkliga exempel användes och sorterades på olika sätt, för att undersöka om stora skillnader i resultatet i matrisen skulle uppenbaras. Det resulterade i sex olika matriser, tre olika sorteringar för två separata dagar av orderplock. Beslutsunderlagets matris visade att Banan var den mest effektiva plockprocessen att använda i den dagliga verksamheten för orderplocket. Anledningen till det var att Stadiumlagret inte plockade skor i de kvantiteter som brytpunkterna efterfrågade. Oavsett hur datan sorteras så övergick aldrig den totala kvantiteten av orderplock de brytpunkterna som hade beräknats. Det var en av sorteringarna som kom närmre brytpunkten än de andra två, men inte tillräckligt nära för att frekvenslägga orderplocket på plocktroget istället för Banan. Rekommendationen till PostNord blev därför att de inte skulle använda plocktorget till det ordinarie orderplocket i den dagliga verksamheten, på grund av att det är mindre effektivt att plocka på plocktorget. Plocktorget kan dock användas som ett komplement till Banan precis som den används i dagsläget. Tillfällen då plocktorget kan användas är när det exempelvis inte finns tillräckligt antal lediga plockplatser på Banan, om artiklarna är för otympliga för att plocka på Banan eller om antalet pieces av en artikel skulle medföra orimligt många påfyllningar av Banans plockplatser.

At least 200,000 m3 of timber are harvested annually using semi-mechanised harvesting systems (SMS) on the Viphya forest plantations in Malawi. Although these systems have long been used on the Viphya, no investigation on their productivity has so far been reported. The absence of local productivity models created uncertainty about the importance of sitebased factors that influence timber harvesting productivity of these systems on the Viphya. Secondly, there is paucity of information regarding the appropriate timber harvesting systems for production maximisation and cost minimisation. This study aimed to develop prediction models for estimating the productivity and costs of semi-mechanised and simulated mechanised timber harvesting systems on the Viphya forest plantations. The study was conducted in Pinus kesiya stands at Kalungulu and Champhoyo forest stations of the Viphya forest plantations. A work study approach was followed to capture harvesting time and volume data. Stepwise multiple regressions were used to develop felling time models for a chainsaw over tree size, inter-tree distance, slope, ground condition, brush density, and ground roughness; and skidding time models over distance, slope, ground condition, ground roughness and volume skidded per cycle for a grapple skidder. Models were statistically validated. Secondary work study data for semi-mechanised systems were simulated for mechanised productivity based on local site factors. The study had shown that diameter at breast height and inter-tree distance were important factors that best explained felling time prediction models in Pinus kesiya stands on the Viphya forest plantations. Similarly, distance from stump to the roadside landing was the most important factor in addition to volume load, slope and ground conditions that determined grapple skidding time. Mechanised systems appear to be more advantageous than semi-mechanised systems. The former are associated with lower operating costs and inventories with relatively high production rates. Therefore, mechanised systems could help to optimise timber harvesting productivity on the Viphya. Further studies should be conducted to determine the effect of different ground conditions and roughness on skidding productivity. / Dissertation (MSc)--University of Pretoria, 2012. / Plant Production and Soil Science / MSc / Unrestricted

With present wage levels already high, and with organized labor demanding still higher wages for the future, it is necessary for management to secure higher productivity from labor in the future than has been secured in the past. In some cases organized labor has demanded that future wage increases be granted with the understanding that such increases will not be followed by compensating price increases. Wage increases without compensating prices increases can be satisfactorily granted only if the wage increases are accompanied by increased labor productivity. At the present time, such increased productivity cannot be obtained by speeding up the operator to an unreasonable pace. Labor will not tolerate such practices. The increased labor productivity necessary to compensate for wage increases must, therefore, be obtained by the use of more efficient production methods. In some cases, increased productivity is secured by the installation of more efficient machinery and equipment. In other cases, particularly with assembly operations, rearrangement of the stock bins, the installation of simple jigs and fixtures, and the revision of work methods to eliminate unnecessary motions and to increase the efficiency of performing the remaining motions may cause considerable increases in labor productivity without unreasonable speed up. This latter method of increasing efficiency is known by various names, some of the more common of which are motion study, methods engineering, and work simplification. The average person usually visualizes modern production as performed almost exclusively by large numbers of workers who constantly repeat the same operation for long periods of time. Doctor Ralph M. Barnes, on page 349 of Motion and Time Study (1), points out that such long-run production is not the typical situation even in larger plants. On the other hand, Doctor Barnes states that most operators work on relatively short-run production with frequent work changes. Any method of increasing the productivity of short-run production would, therefore, be applicable to a wide range of industrial effort. Motion study literature recognizes the fact that, other things being equal, a person tends to perform an operation faster if the work is arranged so that it can be performed by a symmetrical motion path rather than if it is performed by a nonsymmetrical motion path. Small assembly work is usually performed symmetrically by the expedient of arranging the workplace so that each hand builds a complete assembly simultaneously with the other hand. A hand motion path is said to be symmetrical when it meets two requirements. First, at any point in the cycle the right and left hands are equal distances to the right and left respectively of the center line of the body; to fulfill this requirement, components of motion to the right and left of the center line of the body must be performed by the hands moving simultaneously, in opposite directions, and for equal distances. Secondly, at any point in the cycle the right and left hands are equal distances in front of the body; to fulfill this requirement, components of motion toward or away from the body must be performed by the hands moving simultaneously, in the same direction, and for equal distances. Several years ago, while the author was employed as a motion study operations which led him to believe that considerably larger time savings could be made by the application of symmetrical motion paths to short-run production, than could be made on long-run production where the worker changed operations infrequently. It appeared that less practice was required to attain a given level of skill if the motion path were symmetrical than if it were nonsymmetrical. Since, as has already been pointed out, short-run production represents a very large proportion of all industrial effort, it appeared profitable to make a study to determine if the application of symmetrical motion paths would actually yield greater savings on short-run production than on long-run production; any methods producing time savings on short-run production would have a wide field of possible applications. It was the purpose of this study to determine if the impressions mentioned in the preceding paragraph could or could not be verified. An operation was arranged so that it could be performed by either a symmetrical or a nonsymmetrical motion path. Several operators performed short 25-cycle runs of the operation by one motion path and then shifted to the alternate motion path at the end of each 25-cycle run. This procedure was continued until 29 runs by each motion path had been completed by each operator. Such a procedure produced the effect of the operators working on short-term production with frequent changes of operation. All operating times were recorded. A comparison of the time records for the two motion paths gave an index of their relative efficiency. Such comparison did indicate that greater time savings could be expected from the application of symmetrical motion paths to short-run production than by application to long-run production. / Master of Science

Master of Science

Published Article / This paper analyses work sampling and time study as work measurement methods with the view of employing them in an automated labour performance measurement system. These are compared with respect to Hawthorn effect, labour intensiveness, cost, tediousness and knowledge extensiveness. The analysis proves that work sampling is a better option for developing an automated labour performance measurement system that employs computer vision. Web cameras are used to feed real-time images to a central computer via USB extenders. The computer runs a standalone C++ application that uses a random function to establish when measurements are to be taken. The developed video camera footage is converted into a pixel matrix using OpenCV. This matrix is then filtered and analysed, enabling the tracking of a worker. The data generated is stored in text files. After the work sampling period has elapsed, the data is transferred into Microsoft Excel for analysis. Finally a report of the labour utilisation is generated in Microsoft Excel and then send to the analyst for review.

This thesis describes line balancing of indoor optical cable production. First, the thesis explains basics of classical and lean manufacturing management and tools that helps to achieve production line improvement. This theory is the baseline for practical part. With help of analysis of movement of workers and a time study, new standard work that increases line output is set up.

This dissertation argues that the affrication of /t/ and /d/ before /ɹ/ is an active sound change in progress that has been phonologized. Despite numerous references to it in the literature, no experimental work has been undertaken to investigate the phenomenon. This dissertation aims to fill that gap. Conducted over three separate studies, the research presented in subsequent chapters explores three specific questions: Q1: Apparent Time Study – Is the phenomenon of /tɹ/ and /dɹ/ affrication in English a sound change in progress? Q2: Production Study – Are English /t/ and /d/ in /tɹ/ and /dɹ/ clusters articulated like prevocalic [t] and [d], like prevocalic [tʃ] and [dʒ], like neither, or like both? Q3: Perception Study – Do English speakers categorize affricated variants of /t/ found in /tɹ/ clusters as T or CH? Chapter 2 presents results from an Apparent Time Study, which examines sociolinguistic interview data from a corpus of Raleigh, North Carolina English speakers of different ages, all born in the 20th century. The Raleigh corpus is considered to be a suitable choice for conducting this investigation for several reasons. First, it is expected that the phonetic motivation for /tɹ/ and /dɹ/ affrication will be present in any English-speaking community. Second, Raleigh experienced an influx of technology workers to the area from Northern regions of the United States in the middle of the 20th century, following the development of Research Triangle Park (RTP), making it plausible that the resulting dialect contact may have led to the introduction of novel affricated variants to the region. Third, /tɹ/ affrication has been implicated in s-retraction (in /stɹ/ clusters), which is a sound change in progress that has been reported in Raleigh English. The Apparent Time Study aims to determine whether /tɹ/ and /dɹ/ affrication, if present, is a sound change in progress and/or whether the emergence of affricated variants may have been the result of dialect contact. Building on these findings, Chapter 3 presents results from a Production Study conducted in Raleigh, North Carolina, which captures audio, ultrasound, and video data in order to investigate how English speakers’ /tɹ/ and /dɹ/ sequences are coarticulated. The Production Study provides an opportunity to find out how affricated variants of /t/ and /d/ before /ɹ/ are articulated. Chapter 4 presents results from a Perception Study, which explores how listeners (from the Production Study) categorize affricated variants of /t/ spliced from before /ɹ/. Chapter 5 compares results from across studies, and Chapter 6 provides a general discussion and conclusion.

The purpose of this thesis is to analyse the internal transport of a case company and develop a new approach to increase the utilisation rate of their lift trucks. The case study was conducted at a large manufacturing company in southern Sweden and limited to two of their production facilities, denoted PVT and Tage, with a total of 27 lift trucks. The current data provided by the case company imposed limitations on decision-making since it only specified the total number of hours each truck was used in a year. By mapping out the current material handling processes at both facilities, opportunities were identified on how the internal transport can be organised in an economically justifiable way. The empirical data was collected through observations, time studies and interviews. The data was analysed based on the total truck cycle time, idle time and waiting time. The findings highlighted that the lift trucks had low utilisation rate and that there was room for improvements. Through a sensitivity analysis, it was concluded that two trucks from PVT and one truck from Tage could be removed. Additionally, the utilisation rate of the remaining trucks can be increased by letting several production lines share the same truck. For the new suggested internal transport to function properly, the first recommendation is to ensure that the trucks have enough battery capacity, otherwise, truck availability will decrease, making the overall production inefficient. The second recommendation is to eliminate non-value-adding transport activities performed by the machine operators. This can be done by delegating such transport activities to other employees, such as truck drivers and coordinators. These recommendations help the case company to improve efficiencies in their internal transport. Furthermore, the findings highlight the need and possibility for transport efficiency improvements overall and how it can be approached. / Syftet med detta examensarbete är att analysera den interna transporten av ett fallföretag och utveckla ett nytt tillvägagångssätt för att öka utnyttjandegraden av deras truckar. Fallstudien genomfördes vid ett stort tillverkningsföretag i södra Sverige och begränsad till två av deras produktionsverkstäder, betecknade PVT och Tage, med totalt 27 truckar. De aktuella uppgifterna som samlats in på fallföretaget medförde begränsningar på beslutsfattande, eftersom de endast angav det totala antalet timmar varje truck användes under ett år. Genom att kartlägga nuvarande materialhanteringsprocesser vid båda verkstäderna identifierades möjligheter i hur den interna transporten kan organiseras på ett ekonomiskt försvarbart sätt. Empirin samlades in genom observationer, tidsstudier och intervjuer. Data analyserades sedan utifrån truckarnas totala cykeltid, tid för stillastående samt väntetid. Baserat på observationerna och tidsstudierna identifierades truckar som hade låg utnyttjandegrad och således förbättringspotential. Resultatet från känslighetsanalys visade att två truckar från PVT och en truck från Tage kunde elimineras. Utnyttjandegraden på de återstående truckar kan då ökas genom att låta flera produktionslinjer dela på samma truck. För att den nya organisationen av den interna transporten ska fungera korrekt, rekommenderas att alla truckar har tillräcklig batterikapacitet, annars kommer trucktillgängligheten att minskas vilket skulle göra den totala produktionen ineffektiv. Den andra rekommendationen är att eliminera icke värdeskapande transportaktiviteter som utförs av maskinoperatörerna. Detta kan göras genom att delegera sådana transportaktiviteter till andra anställda, såsom truckförare och samordnare. Dessa rekommendationer hjälper fallföretaget att förbättra effektiviteten i sina interna transporter. Vidare visar studien behovet och möjligheten att driva effektivitetsförbättringar samt hur man kan gå till väga för att genomföra det.