Production Line System Research Articles

Lot-sizing in a multi-stage flow line production system with energy consideration

In this paper, a single-item capacitated lot-sizing problem in a flow-shop system with energy consideration is studied. The planning horizon is defined by a set of periods where each one is characterised by a length, an allowed maximal power, an electricity price, a power price and a demand. The objective is to determine the quantities to be produced by each machine at each period while minimising the production cost in terms of electrical, inventory, set-up and power required costs. For medium- and large-scale problems, lot-sizing problems are hard to solve. Therefore, in this study, two heuristics are developed to solve this problem in a reasonable time. To evaluate the performances of these heuristics, computational experiments are presented and numerical results are discussed and analysed.

Towards Systems and Software Product Line Management Implementation in Extended Enterprise

AbstractIn large, transnational organizations like the Airbus Group, which is developing highly complex, long‐leading products and services in multidisciplinary environments, the Systems and Software Product Lines Management (SPL) is of high interest because it offers the capability to manage high levels of commonality between product variants as well as maximize reusability. However, issues like the compatibility of development artefacts from one program to the other and the storage of information in several separated data repositories currently lead to manual treatment of variability and reusability, which is prone to errors, not traceable and being very limited in scope.These issues are likely to become ever more challenging and complex with future programs based on high levels of customization and challenging production ramp‐up to produce complex products in very short term. In such a situation, the faster definition of new product families with the benefits of SPL should encompass the needs to integrate SPL concepts across all engineering phases and artefacts. It should also enable multi‐system requirements with regard to reusability of components or incremental certification and assure efficient development, cost transparency and scalability of the solution space.In this vision paper, we present the initial results of our investigations on Systems and Software Product Line Management based on a thorough survey of State of the Art Theory and Practice approaches discussed in the scientific community and applied by other industries. Consequently we use this information to derive possible perspectives for introducing a systematic and low risk approach for SPL in order to support the divisions of Airbus Group to make a step forward in that direction.

The Generalized Reuse Framework – Strategies and the Decision Process for Planned Reuse

AbstractThe Generalized Reuse Framework is a strategic reuse model for systems engineering management that addresses both investment and leverage of reuse through two interrelated and interacting processes: Development with Reuse (DWR) and Development for Reuse (DFR). This paper summarizes the latest development of this framework from three different angles – taxonomy of reuse, the DWR and DFR categories, reuse strategies and decision processes as applied to incremental system development and product line engineering through a set of planned reuse scenarios.

On the Evolution of Software and Systems Product Line Standards

Software product lines (SPL) have evolved from being a niche research topic to a well-established approach towards development of a family of software-intensive systems, promising better quality in shorter time and less cost. The hall of fame initiative of a 16 year running conference on SPL recognizes exemplary examples of successful application of SPL in practice. However, despite these advances, SPL are seen as quite effort intensive requiring huge initial investments and are not considered as mainstream software development. One of the primary reasons for this is the lack of standardized tools and methods to support development, maintenance and management of SPL. Specifically, every software product line is considered as a stand-alone project with custom tools and methods developed in most of the cases. This leads to a number of diversified, inconsistent and incompatible tools making it difficult to develop new tools or to choose from existing set of tools. It is here that the working group 4 (WG4) of the seventh subcommittee (SC7) titled "Software and Systems Engineering" of the Joint ISO/IEC Technical Committee (JTC1) of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) has proposed a set of interrelated standards in the area of software and systems product lines (SSPL). In this report, we briefly outline the stateof-the-art in software product line tools and motivate the need for standardized tools and methods. We then provide an overview of SSPL standards based on our experience in the last several years. We finally conclude by inviting the entire software engineering community and practitioners to get involved in the critical analysis and creation of SSPLstandards and propel their use in both academia and industry.

Reasoning about Product Lines of Cyber-Physical Systems with Clafer

Reasoning about Product Lines of Cyber-Physical Systems with Clafer

Performance evaluation of WIP-controlled line production systems with constant processing times

We compared three types of WIP-controlled line production systems with constant processing times such as Kanban, CONWIP (constant work-in-process) and DBR (drum-buffer-rope). Based on the observation that such WIP-controlled line production systems are equivalent to m-node tandem queues with finite buffers under communication blocking policy, we applied a max-plus algebra based solution method for the tandem queue to evaluate their performance. Within our knowledge, this research is the first attempt to apply an exact solution method for comparing all three WIP-controlled line production systems at a time. Six-node numerical examples were also used to demonstrate the proposed analysis. The numerical results can be generalized and also provide some insights in designing production systems under certain limited condition.

Mathematical Model of Pulp Washing Using Mathematica

Good washing is the key to a successful closure of the water system in a pulp production line. An improved understanding of associated phenomena, particularly those related to the removal of the very last impurities, is therefore desirable. Therefore a mathematical model describing the desorption phenomenon. The system of governing partial differential equations is solved using Mathematica. Model is simulated using the industrial data. The output thus obtained is compared with the analytic and numerical results of earlier workers. Present technique is simple, elegant and convenient for solving two point boundary value problems with varying range of parameters.

On Formalization of Extended Feature Model using Promotion Technique in Z

Objectives: To investigate automatic analysis of extended feature model with cardinality. Methods/Analysis: Presenting a formal approach to the specification of Ext-FM-WC. In this paper, we propose a promotion technique in Z language for formalizing Software Product Line Systems (SPLS). Findings: The main reason for choosing promotion technique for formalizing SPLS is that applying analysis operations that have promoting manner in large scale feature models is easier. Conclusion/Application: The structure of constructing Ext-FM-WC using promotion technique can has a lot of benefits on analysis operations that have naturally promoting structure.

Max-plus 대수를 이용한 상수 공정시간을 갖는 DBR 라인 생산시스템에서의 대기시간에 대한 간결한 표현식

Although systems with finite capacities have been the topic of much study, there are as of yet no analytic expressions for (higher) moment and tail probability of stationary waiting times in systems with even constant processing times. The normal queueing theory cannot properly handle such systems due to the difficulties caused by finite capacity. In this study, for a DBR (Drum-Buffer-Rope) line production system with constant processing times, we introduce analytic expressions by using previous results obtained using a max-plus algebraic approach.

Implementation of Wireless RFID for Production Line Management System in a Real Environment

The growing number of sales and demands for output in the production line has led to an increase in difficulties in production management. This paper introduces the use of Radio Frequency Identification (RFID) or Automatic Identification (Auto ID) technology at 2.4 GHz frequency to improve the production line management system in the electronics industry. A case study approach was set up, and a test was run in a real industry production line environment using RFID-based systems, namely, passive reader (PR) and passive and active reader (PAR) systems. A comparison between the current system (i.e., barcode-based system) and the RFID-based system in production line showed that PR had 94.7 % efficiency while PAR had 90 % efficiency. The set-up was used to study in depth the functionality, advantages, compatibility, complexity, extendibility, and data output of the developed system. The in-depth test run studied the experience and identified the challenges that will be faced in the development and implementation of a wireless RFID-based system.

A quantitative analysis of the unit verification perspective on fault distributions in complex software systems: an operational replication

Unit verification, including software inspections and unit tests, is usually the first code verification phase in the software development process. However, principles of unit verification are weakly explored, mostly due to the lack of data, since unit verification data are rarely systematically collected and only a few studies have been published with such data from industry. Therefore, we explore the theory of fault distributions, originating in the quantitative analysis by Fenton and Ohlsson, in the weakly explored context of unit verification in large-scale software development. We conduct a quantitative case study on a sequence of four development projects on consecutive releases of the same complex software product line system for telecommunication exchanges. We replicate the operationalization from earlier studies, analyzed hypotheses related to the Pareto principle of fault distribution, persistence of faults, effects of module size, and quality in terms of fault densities, however, now from the perspective of unit verification. The patterns in unit verification results resemble those of later verification phases, e.g., regarding the Pareto principle, and may thus be used for prediction and planning purposes. Using unit verification results as predictors may improve the quality and efficiency of software verification.

On Heijunka Design of Assembly Load Balancing Problem: Genetic Algorithm & Ameliorative Procedure-Combined Approach

Mixed-model straight/U-shaped assembly line has been recognized as a relevant component of Just-In-Time (JIT) production line system. For this system, “Heijunka” design is also challenged as both the task assignment and the production sequence affect the workload imbalance among workstations. In this context and recognizing uncertain task time environment that is often observed in actual manufacturing scene, this research addresses the Line Balancing Problem (LBP) and the Product Sequencing Problem (PSP) jointly and proposes a mathematical model with stochastic task time which is subjected to normal distribution. The objectives of this model are to maximize line efficiency and to minimize the variation of work overload time. A Multi-objective Genetic Algorithm (MOGA) and an Ameliorative Structure of Multi-objective Genetic Algorithm (ASMOGA) with Priority-based Chromosome (PBC) are applied to solve this problem. At last, this research conducts an experimental simulation on a set of benchmark problems to verify the outperformance of the proposed algorithm.

Engineering Mathematical Analysis Method for Productivity Rate in Linear Arrangement Serial Structure Automated Flow Assembly Line

Productivity rate (Q) or production rate is one of the important indicator criteria for industrial engineer to improve the system and finish good output in production or assembly line. Mathematical and statistical analysis method is required to be applied for productivity rate in industry visual overviews of the failure factors and further improvement within the production line especially for automated flow line since it is complicated. Mathematical model of productivity rate in linear arrangement serial structure automated flow line with different failure rate and bottleneck machining time parameters becomes the basic model for this productivity analysis. This paper presents the engineering mathematical analysis method which is applied in an automotive company which possesses automated flow assembly line in final assembly line to produce motorcycle in Malaysia. DCAS engineering and mathematical analysis method that consists of four stages known as data collection, calculation and comparison, analysis, and sustainable improvement is used to analyze productivity in automated flow assembly line based on particular mathematical model. Variety of failure rate that causes loss of productivity and bottleneck machining time is shown specifically in mathematic figure and presents the sustainable solution for productivity improvement for this final assembly automated flow line.

Line Balancing for Improving Apparel Production by Operator Skill Matrix

In this modern world, fashion & styles are changing frequently. The emergence of fast changes in fashion has given rise to shorten production cycle time in the garment industry. To meet the dynamic customer demands of momentous quantities in shorten lead time, assembly line production systems are used, where the garment components are assembled into a finished garment through a sub-assembly process. So in the era of product customization, the optimal usage of resources especially the available facilities & operators who are adding the value of product is important. Therefore the assembly line has to be planned in much more flexible way. This paper deals with the maximum utilization of manpower in labor intensive assembly lines. The objective is to accurately delegate workers to the various operations required to complete the product based on their skill & experience so as to achieve the highest level of productivity and delivery as per planned target. The experimental result showed meaningful improvement in productivity as compared to the existing system.

A systematic test case selection methodology for product lines: results and insights from an industrial case study

In the context of product lines, test case selection aims at obtaining a set of relevant test cases for a product from the entire set of test cases available for a product line. While working on a research-based innovation project on automated testing of product lines of Video Conferencing Systems (VCSs) developed by Cisco, we felt the need to devise a cost-effective way of selecting relevant test cases for a product. To fulfill such need, we propose a systematic and automated test selection methodology using: 1) Feature Model for Testing (FM_T) to capture commonalities and variabilities of a product line; 2) Component Family Model for Testing (CFM_T) to model the structure of test case repository; 3) A tool to automatically build restrictions from CFM_T to FM_T and traces from CFM_T to the actual test cases. Using our methodology, a test engineer is only required to select relevant features through FM_T at a higher level of abstraction for a product and the corresponding test cases will be obtained automatically. We evaluate our methodology by applying it to a VCS product line called Saturn with seven commercial products and the results show that our methodology can significantly reduce cost measured as test selection time and at the same time achieves higher effectiveness (feature coverage, feature pairwise coverage and fault detection) as compared with the current manual process. Moreover, we conduct a questionnaire-based study to solicit the views of test engineers who are involved in developing FM_T and CFM_T. The results show that test engineers are positive about adapting our methodology in their current practice. Finally, we present a set of lessons learnt while applying product line engineering at Cisco for test case selection.

A Semiotic Narratological Approach to the Facilitation of Persona Method for Enhancing User Experience

As digital technology became popular, mass production and consumption underwent a change and customized multiple line production systems and variations in consumption patterns emerged. Consequently, “user-centered designs” that satisfy consumer demands by focusing on consumer preferences became popular. The significance of user interfaces — embedded in electronic devices and computers and improves usability and user control — is coming to the forefront. The User experience, which not only provides elements that are convenient to use but also attempts to trigger emotions such as joy and fun has been receiving recent attention. This study presents methods to correct deficiencies among users by facilitating achievement of individual goals through the actant model, and by supplementing the establishment of a scenario suitable for the user through canonical narrative schema.

A Real Time Quality Monitoring System for Engineering Industry: A Practical and Rapid Approach Using Embedded Vision System with LabVIEW

With increased expectations for engineering products of high quality and safety standards, the need for accurate, fast and objective quality determination of these characteristics in engineering products continues to grow. Embedded vision provides one alternative for an automated, non-destructive, fast and cost-effective technique to accomplish these requirements. In this work, the authors are developed an integrated system which has two major components: an Embedded Vision System (EVS) and a Real Time Monitoring System (RTMS). This work describes design and development of prototyped Production Line System (PLS) based on a practical and fast approach using EVS and LabVIEW with IMAQ Vision Assistant as image processing tool. Experimental results show that this integrated system is faster and produces a lower error rate than humans produce in the quality inspection process.

Energy Efficiency Management of an Integrated Serial Production Line and HVAC System

Modern manufacturing facilities waste many energy savings opportunities (ESO) due to the lack of integration between the facility and the production system. To explore the energy savings opportunities, this paper combines the two largest energy consumers in a manufacturing plant: the production line and the heating, ventilation, and air conditioning (HVAC) system. The concept of the energy opportunity window (OW) is utilized, which allows each machine to be turned off at set periods of time without any throughput loss. The recovery time of each machine is the minimum amount of time a machine must be operational between opportunity windows to guarantee zero production loss and it is explored both analytically and numerically. The opportunity window for the production line is synced with the peak periods of energy demand for the HVAC system to create a heuristic rule to optimize the energy cost savings. This integrated system is modeled and tested using simulation studies.

Design of PLC Control System in Automatic Production Line for Casing Fin Tube

Finned tube is a kind of highly efficient heat exchange component, widely used in heat exchanger. In order to improve the automation level of finned tube production line, this paper, according to the composition of finned tube production line and the function of each part, designed the control scheme of the production line, including motor drive technology, hydraulics technology, PLC control technology etc. The control scheme makes raw material of aluminum sheet feeding, punching, shearing, winged, tube expanding process to form a whole, which improved the efficiency of the production line and the processing precision.

Optimization of the Automobile Parts Mixed Production Line Based on EM-Plant

The balance of mixed production line is the key issue, which means to adjust the working load to make working hour equal to production TAKT as well as to average the working hour of each station. Firstly, the automobile piston mixed production line system was analyzed by eM-Plant, which was carried out by object-oriented modeling and process-oriented simulation. After evaluating the production line performance, including the utilization rate of equipment and worker, the bottlenecks of the mixed production line were indentified. Finally, the relative measures were put forward to solve it, which makes the enterprise obtains the ability of rapid response to market demands.