One of the universal characteristics of all organization concerns their attempts to achieve high product quality at low price. For that reason, the contemporary organizations direct their attempts to improve the utilization of workers’ potential and adopt the line-stopping strategies at the shop .The research presented in this thesis aims at analyzing and revealing to what extent the decisions at the shop floor depend on operators. The conclusions drawn in this paper contribute to determination of the scope of operators’ responsibilities and examination of the ways in which workers maintain the process uninterrupted. The role of operators for attaining the desired product quality is presented as well. These objectives have been accomplished through theoretical work.

O desempenho dos sistemas de Planejamento e Controle de Produção e dos sistemas de Planejamento e Controle de Chão-de-Fábrica é fortemente dependente da qualidade e confiabilidade dos dados de operação e da rapidez com que estes dados são obtidos para análise e acompanhamento da execução dos planos de produção. O processo de coleta e tratamento destes dados tem sido pouco detalhado nos modelos de referência encontrados na literatura. Este trabalho posicionou a utilização de sistemas supervisórios para a coleta de dados de produção em sistemas de planejamento e controle no ambiente da manufatura discreta, propondo um roteiro de atividades a serem consideradas no desenvolvimento de sistemas de planejamento. / The Production Planning and Control Systems and Shop Floor Control Systems performance are extremely dependent of the quality and reliability of the operational data and readiness in data collection process, in order to provide information to analyse the execution of production plans. The data collection process has been pour detailed in the reference models found in literature. This work locates the supervisory and control data acquisition systems role in the landscape of discrete manufacturing planning systems and proposes a routing of tasks to be considered in developing process of a manufacturing planning system.

O Sistema de Execução da Manufatura (MES Manufacturing Execution System) é uma ferramenta aplicada no chão-de-fábrica que permite visualizar e monitorar processos em tempo real, fornecendo informações que levam a uma melhor eficiência operacional. Este trabalho apresenta uma pesquisa exploratória, realizada em uma empresa de usinagem e montagem de médio porte, tendo o objetivo analisar a implantação do MES para auxiliar a tomada de decisão referente à gestão de equipamentos e recursos produtivos. O trabalho também compara dois sistemas de controle de produção: o MES com o sistema realizado de forma manual (planilhas eletrônicas) utilizado antes da implantação. As informações que serviram de base para a análise da implantação foram coletadas por meio de questionário de avaliação e validadas por um grupo de discussão. Entre os resultados alcançados, identificaram-se: i) as vantagens do MES em relação ao sistema manual, ii) a eficácia da implantação, iii) melhoria dos resultados operacionais, iv) pontos positivos e negativos da implantação e aplicação. / The MES (Manufacturing Execution System) is a tool used in shop-floor that allows you to view and monitor processes in real time, providing information that leads to better operational efficiency. This paper presents an exploratory research, conducted in a medium size company of machining and assembly, with objective to analyze the implementation of MES to assist in decision making concerning the management of equipment and production resources. The study also compares two systems of production control; the MES with the system carried out manual (spreadsheet) used prior to implementation. The information basis for the analysis of the implementation were collected through questionnaire evaluation, validated by a discussion group. Among the results, it was identified: i) the benefits of MES in the manual system, ii) the effectiveness of implementation, iii) improving operating results, iv) positive and negative effects of deployment and application.

Em um ambiente produtivo, a falta de informações confiáveis cria, muitas vezes, uma imagem do chão-de-fábrica que não retrata a realidade, comprometendo o desempenho e diminuindo a agilidade da empresa. Neste contexto, um sistema de supervisão do chão-de-fábrica, capaz de fornecer informações confiáveis e de forma rápida, pode ser um grande diferencial para manter a competitividade das empresas de manufatura. Este trabalho sistematiza visões e conceitos que auxiliam na implantação de sistemas de supervisão do chão-de-fábrica em empresas que utilizam operações de usinagem no seu processo produtivo. Além disso, apresenta o desenvolvimento e a implantação deste sistema na Fábrica Integrada Modelo (FIM) do Núcleo de Manufatura Avançada (NUMA) da Escola de Engenharia de São Carlos - USP. / The lack of reliable information in a production environment creates a wrong image of the shop floor, affecting the plant\'s agility and its performance. A shop floor supervisory system, able to provide, in a fast way, that sort of information, can enhance the competitiveness of the manufacturing plant. The present work shows visions and concepts that can give support to the implementation of shop floor supervisory system in manufacturing plants. lt also presents the development and implementation of this kind of system in the lntegrated Model Plant (FIM) of the Advanced Manufacturing Nucleus (NUMA) at São Carlos - University of São Paulo.

Abstract During the last decades significant changes in the buying behavior of customers can be observed. While in former days price sensitivity lead to more uniformed products, in present days manifold high-quality products and customization with reasonable prices and rapid delivery are demanded. As a consequence, the industry asks for manufacturing systems which allow for fast ramp-up, multi-variant production and rapid adaptability. In this environment, several scientific approaches such as agent-based and holonic manufacturing systems have been investigated within the last years. In order to cover all aspects of the foreseen future demands, the architectures for such systems are very complex and the system’s entities are characterized by very flexible behavior. Hence, the efforts for their implementation are rather high and the systems tend to exhibit non-deterministic behavior. Furthermore, the top down approach of most systems leads to a complete re-organization of the factory management. As a consequence the acceptance for such systems in real industrial environment at present day is very limited. Therefore, the objective of this thesis is to develop an architecture for flexible manufacturing systems which allows for easy take-up in the industry. It is based on a bottom-up approach with a new kind of flexible, intelligent shop-floor components called Manufactrons. The architecture covers all layers of traditional factory organization with special emphasis on the shop floor organization. The approach and results are based on the research activities of the European Research Project XPRESS in which representatives of three major industry branches collaborated in order to find a solution for their future demands on flexible manufacturing systems. The architecture has been implemented in the context of XPRESS in aerospace, automotive and electrical industry. The tests show the feasibility of the approach. The capability for a smooth integration of the new approach into existing manufacturing environment has successfully been demonstrated. / Tiivistelmä Viime vuosikymmeninä asiakkaiden ostokäyttäytyminen on muuttunut merkittävästi. Ennen asiakkaiden hintatietoisuus johti yhtenäisiin tuotteisiin, kun taas nykyään vaaditaan moninaisempia tuotteita ja muokattavuutta kohtuulliseen hintaan. Samaan aikaan odotetaan korkealaatuisia tuotteita ja nopeaa toimitusta. Nämä seikat ovat aiheuttaneet tuotantoteollisuudelle uusia haasteita. Reagoidakseen nopeasti asiakkaiden vaatimuksiin tuotannonsuunnittelussa on alettu keskittymään korkealaatuisten tuotemuunnelmien määrän kasvattamiseen. Tämän vuoksi tarvitaan tuotantojärjestelmiä, jotka mahdollistavat nopean Ramp Up -prosessin, moneenmuuntuvan tuotannon ja nopean mukautuvuuden. Tätä aihetta on viime vuosina lähestytty esimerkiksi agentteihin perustuvien ja holonisten tuotantojärjestelmien kautta. Kuitenkin näihin tulevaisuuden haasteisiin pystytään vastaamaan vain kompleksisilla arkkitehtuureilla ja järjestelmän entiteeteille ominaisia ovat hyvin mukautuvat käyttäytymismallit. Näiden toteuttamiseen tarvitaan paljon työtä ja järjestelmillä on tapana käyttäytyä epä-deterministisesti. Lisäksi ylhäältä alas lähestymistapa johtaa usein tehtaan täydelliseen uudelleenorganisointiin, minkä vuoksi lähestymistapaa ei suosita oikeissa teollisuusympäristöissä. Tämän väitöstyön tarkoituksena on kehittää mukautuville tuotantojärjestelmille arkkitehtuuri, joka mahdollistaa järjestelmien helpon käyttöönoton teollisuudessa. Arkkitehtuuri perustuu alhaalta ylös -lähestymistapaan ja sisältää uudenlaisen joustavan ja älykkään tuotantotilakomponentin, manufactronin. Arkkitehtuuri kattaa kaikki perinteisen tehdasorganisaation kerrokset keskittyen kuitenkin erityisesti tuotantotilojen organisointiin. Lähestymistapa ja tulokset perustuvat Euroopan Unionin XPRESS-tutkimusprojektiin. Projektissa tehtiin yhteistyötä kolmen suuren teollisuushaaran kanssa tarkoituksena löytää joustava tuotantojärjestelmäratkaisu tulevaisuutta varten. Arkkitehtuuria sovellettiin XPRESS-projektissa lentokone-, auto- ja elektoniikkateollisuuteen ja testit osoittivat lähestymistavan soveltuvuuden. Myös lähestymistavan sujuva integrointi olemassa oleviin teollisuusjärjestelmiin osoitettiin onnistuneesti.

This thesis focuses on analysis and improvement of the process of production order. The solution is implementation of Shop floor management system in a production workshop. It is presented as a project based on analysis of the company and the order process. The project consists of a draft of implementation during continuous operations and costs calculation for implementation of the system.

Introduction The paradigm shift in manufacturing that Industry 4.0 brings forth with new advanced technologies and the rapid growth of sensing and controlling technologies enable further visualization and optimization that can contribute to achievingimproved decision-making in manufacturing. A significant new capability is the ability to construct a Digital Twinthat connects the physical and virtual space. However, there are still confusion and obscurity regarding what Digital Twinis and how it can becreated and then used to create value for the company. Therefor the purpose of the thesis is to examine how manufacturing companies can utilize the implementation of Digital Twinand assess Digital Twinin a shop-floor. ➢RQ1: How can DT be beneficial to increase business value in a manufacturing company? ➢RQ2: What changes need to be done in the shop-floor to implement Digital Twin? Methodology A literature review was conducted to provide previous researchand contextwithin the area of Digital Twin. A multiple-case studywas performed at three case companies to gain meaningful insight from a real-world perspective, semi-structured interviews, dialogs, and observations were conductedat the case companies. The analysis was then performed by examining similarities, and dissimilarities between theoretical and empirical data, as well as opportunities in theoretical findings that correspond with challenges in empirical findings. Frame of Reference The literature review increased the authors’ understanding of the research topic and gave context to the concept of Digital Twin. The review is mainly focused on the Digital Twintechnologyand how it is constructed, as well as the applicationsareas. Empirical Findings The empirical findings provide an overview of boththe current and future state of the case companies in relation to organizational, operational, and technological factors. Additionally, it provides a deeper understanding of how shop-floor management is designed at one of the case companies. Analysis The combination of the Frame of Reference and Empirical Findings contributewith important insight on the potential benefits that can be created through the utilizationof Digital Twin, as well as what is requiredin the shop-floor to enable implementation ofDigital Twin. Conclusions The value that can be created utilizing Digital Twinis outlinedand a clearer definition is proposed to avoid misunderstandings and confusion. Requirements that need to be achieved for a successful implementation arecovered as well. A future recommendation is measuring resources and effort in relation to the created value of a Digital Twin.

During the 1990s two contrasting paths to the organization of work have emerged in the Swedish engineering industry: the structure-conservative and structure-innovative. This thesis deals with the latter, and focuses primarily on necessary changes in management control systems that support structureinnovative forms of team-organized work. Three types of management control systems are studied in this thesis: performance management and measurement systems, systems for continuous improvements and wage systems. The empirical base of this thesis consists of data from an exploratory survey study as well as a multiple case study. On a general level, the survey study indicates a lack of congruence between structure and systems. Many companies seem to have started to move along the structure-innovative path but have not changed the management control systems accordingly. However, there are good reasons for doing so. The companies that have chosen the structure-innovative path perform better in terms of productivity, quality and cost reduction. These are also the companies that have changed their management control systems to the greatest extent. The case study provides examples of how management control systems may be changed to fit structure-innovative forms of team-organized work. The main focus has been on the use of Balanced Scorecard. How a strategic continuous improvement capability was developed and sustained in the studied companies is illustrated. The findings extend previous research on new production concepts, which, this thesis argues, are not to be regarded as an issue of technology and vertical division of labour only, but also of supportive management control systems. / <p>QC 20100525</p>

The research work presented in this dissertation relates to lot sizing and its applications in the areas of operational planning and shop floor scheduling and control. Lot sizing enables a proper loading of requisite number of jobs on the machines in order to optimize the performance of an underlying production system. We address lot sizing problems that are encountered at the order entry level as well as those that are faced at the time of distributing the jobs from one machine to another and those that arise before shipping the jobs (orders) to customers. There are different issues and performance measures involved during each of these scenarios, which make the lot sizing problems encountered in these scenarios different from one another. We present algorithms and relevant theoretical analyses for each of the lot sizing problems considered, and also, present results of numerical experimentation to depict their effectiveness We first study the lot sizing problem encountered while transferring jobs from one machine to another. A lot of the jobs is to be split into smaller lots (called sublots) such that the lot is processed on multiple machines in an overlapping manner, a process which is known in the literature as lot streaming. Two lot streaming problems, FL2/n/C and FLm/1/C, are investigated in Chapter 2. FL2/n/C involves a two-machine flow shop in which multiple lots are to be processed. The objective is to minimize the combined cost of makespan and material handling (the latter is proportional to the number of sublots). A dynamic programming-based methodology is developed to determine the optimal sublot sizes and the number of sublots for each lot while assuming a known sequence in which to process the lots. We designate this problem as LSP-DP. This methodology is, then, extended to determine an optimal sequence in which to process the lots in conjunction with the number of sublots and sublot sizes for each lot. We designate this problem as LSSP-DP. Three multidimensional heuristic search procedures (denoted as LSSP-Greedy, LSSP-Cyclic and LSSP-ZP) are proposed for this problem in order to obtain good-quality solutions in a reasonable amount of computational time. Our experimentation reveals that both lot streaming and lot sequencing generate significant benefits, if used alone. However, for the objective of minimizing total handling and makespan cost, lot streaming is more beneficial than lot sequencing. The combined use of lot streaming and sequencing, expectedly, results in the largest improvement over an initial random solution. LSP-DP is found to be very efficient, and so are the three LSSP heuristics, all of which are able to generate near-optimal solutions. On the average, LSSP-Greedy generates the best solutions among the three, and LSSP-Cyclic requires the least time. FLm/1/C deals with the streaming of a single lot over multiple machines in a flow shop. The objective is a unified cost function that comprises of contributions due to makespan, mean flow time, work-in-process, transfer time and setup time. The distinctive features of our problem pertain to the inclusion of sublot-attached setup time and the fact that idling among the sublots of a lot is permitted. A solution procedure that relies on an approximation equation to determine sublot size is developed for this problem for equal-size sublots. The approximation avoids the need for numerical computations, and enables the procedure to run in polynomial time. Our experimentation shows that this solution procedure performs quite well and frequently generates the optimal solution. Since the objective function involves multiple criteria, we further study the marginal cost ratios of various pairs of the criteria, and propose cost sensitivity indices to help in estimating the impact of marginal cost values on the number of sublots obtained. The lot sizing problem addressed in Chapter 3 is motivated by a real-life setting associated with semiconductor manufacturing. We first investigate the integration of lot sizing (at the operational planning level) and dispatching (at the scheduling and control level) in this environment. Such an integration is achieved by forming a closed-loop control system between lot sizing and dispatching. It works as follows: lot sizing module determines lot sizes (loading quota) for each processing buffer based on the current buffer status via a detailed linear programming model. The loading quotas are then used by the dispatching module as a general guideline for dispatching lots on the shop floor. A dispatching rule called "largest-remaining-quota-first" (LRQ) is designed to drive the buffer status to its desired level as prescribed by the lot sizing module. Once the buffer status is changed or a certain amount of time has passed, loading quotas are updated by the lot sizing module. Our experimentation, using the simulation of a real-life wafer fab, reveals that the proposed approach outperforms the existing practice (which is based on "first-in-first-out" (FIFO) model and an ad-hoc lot sizing method). Significant improvements are obtained in both mean values and standard deviations of the performance metrics, which include finished-goods inventory, backlog, throughput and work-in-process. The integration of lot sizing and dispatching focuses on the design of an overall production system architecture. Another lot sizing problem that we present in Chapter 3 deals with input control (or workload control) that complements this architecture. Input control policies are responsible for feeding the production system with the right amount of work and at the right time, and are usually divided into "push" or "pull" categories. We develop a two-phase input control methodology to improve system throughput and the average cycle time of the lots. In phase 1, appropriate operational lot sizes are determined with regard to weekly demand, so as to keep the lot start rate at the desired level. In phase 2, a "pull" policy, termed CONLOAD, is applied to keep the bottleneck's workload at a target level by releasing new lots into the system whenever the workload level is below the desired level. Since the operators are found to be the bottleneck of the system in our preliminary investigation, the "operator workload" is used as system workload in this study. Using throughput and cycle time as the performance metrics, it is shown that this two-phase CONLOAD methodology achieves significant improvement over the existing CONWIP-like policy. Furthermore, a reference table for the target operator workload is established with varying weekly demand and lot start rate. The last lot sizing problem that we address has to do with the integration of production and shipping operations of a make-to-order manufacturer. The objective is to minimize the total cost of shipping and inventory (from manufacturer's perspective) as well as the cost of earliness and tardiness of an order (from customer's perspective). An integer programming (IP) model is developed that captures the key features of this problem, including production and delivery lead times, multiple distinct capacitated machines and arbitrary processing route, among others. By utilizing the generalized upper bound (GUB) structure of this IP model, we are able to generate a simplified first-level RLT (Reformulation Linearization Technique) relaxation that guarantees the integrity of one set of GUB variables when it is solved as a linear programming (LP) problem. This allows us to obtain a tighter lower bound at a node of a branch-and-bound procedure. The GUB-based RLT relaxation is complemented by a GUB identification procedure to identify the set of GUB variables that, once restricted to integer values, would result in the largest increment in the objective value. The tightening procedure described above leads to the development of a RLT-based branch-and-bound algorithm. Our experimentation shows that this algorithm is able to search the branch-and-bound tree more efficiently, and hence, generates better solutions in a given amount of time. / Ph. D.

In this study a time based bidding framework is developed which is used for dispatching jobs to manufacturing resources in a virtual shop-floor environment. Agent-based shop-floor control approach is implemented with machine and part agents. The Contract-net communication protocol is utilized as the negotiation scheme between these agents. Single step product reservation (SSPR) technique is adopted throughout the study. Primary objective is determined as meeting the due dates and if the lateness is inevitable, avoiding the parts of high priority from being late. A balanced machine utilization rate is set as the secondary objective. During bid construction step, the SSPR technique is augmented with W(SPT+CR) sequencing rule in order to obtain weighted tardiness results. Bids containing Earliest Finishing Time (EFT) and machine loading values of the corresponding machine are evaluated with considering the priority of the part. An elimination algorithm which discards the highly deviated bids having obvious differences is implemented at the initial stage of the bid evaluation step. A basic algorithm to control the maximum tardiness value is applied, as well. A simulation test bed is developed in order to implement the time concept into the presented bidding framework. The test bed is mainly based on the Computer Integrated Manufacturing Laboratory (CIMLAB) located in Middle East Technical University, Department of Mechanical Engineering. The developed bidding algorithm is tested under several cases. Results revealed that the proposed bidding framework was quite successful in meeting the objectives. The study is concluded with some specific future work, outlined in the light of the results obtained.