Algorithm and Simulation of Holonic Worker Selection Guide with Case Study on Task Urgency and Skill Rating

This paper explicates the Worker Selection Guide (WOSEG), that is, a functional branch of Holonic Workforce Allocation Model (HWM). A case study is conducted on reckoning the task urgency and skill rating parameters in a job-shop setting, from which the workforce performance data are acquired. The destined performance measures encompass overdue rate, average skill level, interpersonal and intrapersonal skill deviations, which can be generated via computer simulation. The corresponding simulation model is built with the software of Witness, Visual Basic, and Microsoft Access for the input instruction coding and output analysis purposes. Keywords: Holonic manufacturing, worker selection, algorithm, simulatio

MODELING OF AN AIR-BASED DENSITY SEPARATOR

There is a lack of fundamental studies by means of state of the art numerical and scale modeling techniques scrutinizing the theoretical and technical aspect of air table separators as well as means to comprehend and improve the efficiency of the process. The dissertation details the development of a workable empirical model, a numerical model and a scale model to demonstrate the use of a laboratory air table unit. The modern air-based density separator achieves effective density-based separation for particle sizes greater than 6 mm. Parametric studies with the laboratory scale unit using low rank coal have demonstrated the applicability with regards to finer size fractions of the range 6 mm to 1 mm. The statistically significant empirical models showed that all the four parameters, i.e, blower and table frequency, longitudinal and transverse angle were significant in determining the separation performance. Furthermore, the tests show that an increase in the transverse angle increased the flow rate of solids to the product end and the introduction of feed results in the dampening of airflow at the feed end. The higher table frequency and feed rate had a detrimental effect on the product yield due to low residence time of particle settlement. The research further evaluated fine particle upgrading using various modeling techniques. The numerical model was evaluated using K-Epsilon and RSM turbulence formulations and validated using experimental dataset. The results prove that the effect of fine coal vortices forming around the riffles act as a transport mechanism for higher density particle movement across the table deck resulting in 43% displacement of the midlings and 29% displacement of the heavies to the product side. The velocity and vector plots show high local variance of air speeds and pressure near the feed end and an increase in feed rate results in a drop in deshaling capability of the table. The table was further evaluated using modern scale-modeling concepts and the scaling laws indicated that the vibration velocity has an integral effect on the separation performance. The difference between the full-scale model and the scaled prototype was 3.83% thus validating the scaling laws

Performance Evaluation of In-storage Processing Architectures for Diverse Applications and Benchmarks

University of Minnesota Ph.D. dissertation.June 2018. Major: Electrical/Computer Engineering. Advisor: David Lilja. 1 computer file (PDF); vii, 100 pages.As we inch towards the future, the storage needs of the world are going to be massive and diversied. To tackle the needs of the next generation, the storage systems are required to be studied and require innovative solutions. These solutions need to solve multitude of issues involving high power consumption of traditional systems, manageability, easy scaling out, and integration into existing systems. Therefore, we need to rethink the new technologies from the ground up. To keep the energy signature under control we devised a new architecture called Storage Processing Unit (SPU). For the modeling of this architecture we incorporate a processing element inside the storage medium to limit the data movement between the storage device and the host processor. This resulted in a hierarchal architecture which required an extensive design space exploration along with in-depth study of the applications. We found this new architecture to provide energy savings from 11-423X and gave performance gains from 4-66X for applications including k-means, Sparse BLAS, and others. Moreover, to understand the diverse nature of the applications and newer technologies, we tried the concept of in-storage processing for unstructured data. This type of data is demonstrating huge amount of growth and would continue to do so. Seagate's new class of drives - Kinetic Drives, address the rise of unstructured data. They have a processing element inside disk drives that execute LevelDB, a key-value store. We evaluated this off-the-shelf device using micro and macro benchmarks for an in-depth throughput and latency benchmarking. We observed sequential write throughput of 63 MB/sec and sequential read throughput of 78 MB/sec for 1 MB value sizes. We tested several unique features including P2P transfer that takes place in a Kinetic Drive. These new class of drives outperformed traditional servers workloads for several test cases. Finally, large number of these devices are needed for huge amounts of data. To demonstrate that Kinetic Drives reduce the management complexity for large-scale deployment, we conducted a study. We allocated large amounts of data on Kinetic Drives and then evaluated the performance of the system for migration of data amongst drives. Previously developed key indexing schemes were evaluated which gave important insights into their performance differences. Based on this study we can conclude that efficient mapping of key-value pairs to drives could be obtained. This lead to an understanding of the trade-offs between the number of empty drives and mapping of different key ranges to different drives. In conclusion, in-storage processing architectures bring an interesting aspect where processing is moved closer to the data. This leads to a paradigm shift which often results in a major software and hardware architectural changes. Furthermore, the new architectures have the potential to perform better than the traditional systems but require easy integration with the existing systems

A decision model for manufacturing best practice adoption : linking practices to competitive strategies

This thesis describes research that has developed a decision model for the analytical selection of manufacturing best practices. The competitiveness and growth in the manufacturing sector is critical for Singapore economy. Design and improvement of manufacturing systems is imperative to sustain the competitiveness of manufacturing organisations in the country. It is common for companies to adopt manufacturing best practices in this design process to emulate the success and performance of their counterparts. However, practices should be adapted to the competitive environment and strategy of the company to yield the desired results. Therefore, linkages between best practices and their associated competitive priorities will present useful guidelines for action to help manufacturing organisations achieve superior performance. The research programme has set out to define a decision model for best practice adoption. A broad taxonomy of manufacturing strategies and concepts has been used to identify and cluster a list of popular best practices commonly adopted. The decision framework for best practice adoption process is then formulated and a preliminary decision model constructed. This model is verified through semistructured interviews with industry and academic experts. Validation of model is conducted via case study research on eight manufacturing organisations. Linkages between practices and competitive strategies are then constructed to establish the final decision model. Finally, this decision model is illustrated in the form of a guidebook to help practitioner in the best practice selection process. This research has bridged the fields of manufacturing strategy and best practice research by establishing a comprehensive taxonomy of manufacturing strategies and concepts to classify the popular and commonly adopted best practices. A decision model that links best practices to competitive strategies has been developed to select the most appropriate practices for an environment. Thus, the work presented in this thesis has made a significant and original contribution to knowledge on the provision of analytical decision support for practitioners engaging in the manufacturing best practice adoption process.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Functional Design of Physical Internet Facilities: A Road-rail Hub

As part of the 2010 IMHRC, Montreuil, Meller and Ballot enumerated the type of facilities that would be necessary to operate a Physical Internet (PI, π), which they termed, “π-nodes.” This paper is part of a three-paper series for the 2012 IMHRC where the authors provide functional designs of three PI facilities. This paper covers a PI road-rail hub. The purpose of a PI road-rail node is to enable the transfer of PI containers from their inbound to outbound destinations. Therefore, a road-rail π-hub provides a mechanism to transfer π-containers from a train to another one or a truck or from a truck to a train. The objective of the paper is to provide a design that is feasible to meet the objectives of this type of facility, identify ways to measure the performance of the design, and to identify research models that would assist in the design of such facilities. The functional design is presented in sufficient detail as to provide an engineer a proof of concept

Big data analytics for intra-logistics process planning in the automotive sector

The manufacturing sector is facing an important stage with Industry 4.0. This paradigm shift impulses companies to embrace innovative technologies and to pursuit near-zero fault, near real-time reactivity, better traceability, and more predictability, while working to achieve cheaper product customization. The scenario presented addresses multiple intra-logistic processes of the automotive factory Volkswagen Autoeuropa, where different situations need to be addressed. The main obstacle is the absence of harmonized and integrated data flows between all stages of the intra-logistic process which leads to inefficiencies. The existence of data silos is heavily contributing to this situation, which makes the planning of intra-logistics processes a challenge. The objective of the work presented here, is to integrate big data and machine learning technologies over data generated by the several manufacturing systems present, and thus support the management and optimisation of warehouse, parts transportation, sequencing and point-of-fit areas. This will support the creation of a digital twin of the intra-logistics processes. Still, the end goal is to employ deep learning techniques to achieve predictive capabilities, all together with simulation, in order to optimize processes planning and equipment efficiency. The work presented on this thesis, is aligned with the European project BOOST 4.0, with the objective to drive big data technologies in manufacturing domain, focusing on the automotive use-case

Simulation and optimization techniques applied in semiconductor assembly and test operations

The importance of back-end operations in semiconductor manufacturing has been growing steadily in the face of higher customer expectations and stronger competition in the industry. In order to achieve low cycle times, high throughput, and high utilization while improving due-date performance, more effective tools are needed to support machine setup and lot dispatching decisions. In previous work, the problem of maximizing the weighted throughput of lots undergoing assembly and test (AT), while ensuring that critical lots are given priority, was investigated and a greedy randomized adaptive search procedure (GRASP) developed to find solutions. Optimization techniques have long been used for scheduling manufacturing operations on a daily basis. Solutions provide a prescription for machine setups and job processing over a finite the planning horizon. In contrast, simulation provides more detail but in a normative sense. It tells you how the system will evolve in real time for a given demand, a given set of resources and rules for using them. A simulation model can also accommodate changeovers, initial setups and multi-pass requirements easily. The first part of the research is to show how the results of an optimization model can be integrated with the decisions made within a simulation model. The problem addressed is defined in terms of four hierarchical objectives: minimize the weighted sum of key device shortages, maximize weighted throughput, minimize the number of machines used, and minimize makespan for a given set of lots in queue, and a set of resources that includes machines and tooling. The facility can be viewed as a reentrant flow shop. The basic simulation was written in AutoSched AP (ASAP) and then enhanced with the help of customization features available in the software. Several new dispatch rules were developed. Rule_First_setup is able to initialize the simulation with the setups obtained with the GRASP. Rule_All_setups enables a machine to select the setup provided by the optimization solution whenever a decision is about to be made on which setup to choose subsequent to the initial setup. Rule_Hotlot was also proposed to prioritize the processing of the hot lots that contain key devices. The objective of the second part of the research is to design and implement heuristics within the simulation model to schedule back-end operations in a semiconductor AT facility. Rule_Setupnum lets the machines determine which key device to process according to a machine setup frequency table constructed from the GRASP solution. GRASP_asap embeds a more robust selection features of GRASP in the ASAP model through customization. This allows ASAP to explore a larger portion of the feasible region at each decision point by randomizing machine setups using adaptive probability distributions that are a function of solution quality. Rule_Greedy, which is a simplification of GRASP_asap, always picks the setup for a particular machine that gives the greatest marginal improvement in the objective function among all candidates. The purpose of the third part of the research is to statistically validate the relative effectiveness of our top six dispatch rules by comparing their performance on 30 real and randomly generated data sets. Using both GRASP and our ASAP discrete event simulation model, we have (1) identified the general order of dispatch rule performance, (2) investigated the impact of having setups installed on machines at time zero on rule performance, (3) determined the conditions under which restricting the maximum number of changeover affects the rule performance, and (4) studied the factors that might simultaneously affect rule performance with the help of a common random numbers experimental design. In the analysis, the first two objectives, weighted key device shortages and weighted throughput, are used to measure outcomes.Operations Research and Industrial Engineerin