Implications of automation in engineer-to-order production:a case study

In order to retain a certain level of production in Norway,suppliers to the Norwegian maritime industry need to lower their production costs.Automation is generally an effective way of achieving this in standardized high-volume,low variety production.However,manufacturing companies in the Norwegian maritime industry typically supply capital-intensive,advanced and customized products in low volumes.In this engineer-to-order production situation,manual labor is traditionally preferred over automation.Nonetheless,such companies increasingly automate parts of their production.This paper presents a case of a supplier that has chosen to automate its welding operations,the implications and determinants of this decision.     

A framework for diagnosing the delivery reliability performance of make-to-order companies

Improving performance in terms of delivery reliability is increasingly important for make-to-order (MTO) companies. Detecting improvement opportunities requires a structured diagnosis of the current performance. General problem-solving literature provides structures for diagnosis processes in general, but – depending on the performance problem to be diagnosed – a theoretical framework based on domain-specific scientific knowledge is required. This paper presents a framework for diagnosing delivery reliability performance in MTO companies. The framework consists of a diagnosis tree that structures the diagnosis process, enabling one to navigate from the achieved performance to the underlying causes related to production planning and control (PPC). A theoretical foundation, enabling the possible causes of unreliable deliveries to be structured, is based on recent scientific developments in PPC literature. Three case studies exemplify the use of the framework. The developed framework shows its particular strengths in (1) selecting the right problem areas, (2) providing the right diagnosis instruments, and (3) detecting causes related to PPC decisions. It also supports diagnosis from quantitative data available in standard ERP software packages and enables diagnosis triangulation using qualitative data from the underlying decision processes.     

A capacity-oriented hierarchical approach to single-item and small-batch production planning using project-scheduling methods

Most production planning and control (PPC) systems used in practice have an essential weakness in that they do not support hierarchical planning with feedback and do not observe resource constraints at all production levels. Also, PPC systems often do not deal with particular types of production, for example, low-volume production. We propose a capacity-oriented hierarchical approach to single-item and small-batch-production planning for make-to-order production. In particular, the planning stages of capacitated master production scheduling, multi-level lot sizing, temporal and capacity planning, and shop floor scheduling are discussed, where the degree of aggregation of products and resources decreases from stage to stage. It turns out that the optimization problems arising at most stages can be modelled as resourceconstrained project scheduling problems.     

Approaching lean product development using system dynamics:investigating front-load effects

Competing with successful products has become perplexing with several uncertainties and transmutes from time to time as customers’ expectations are
dynamic. That is why manufacturing firms exhaustively strive to look for a better competitive frontier using wellestablished and innovative product development (PD) processes. In this paper, we would like to answer three research questions: (i) What would be the effects of frontloading
in PD? (ii) Can we improve our PD process endlessly? (iii) When is the critical time that the firm should take remedial action for improvements? As a contribution to the vast numbers of improvement methods in new product development (NPD), this paper investigates the effects of front-loading using set-based concurrent engineering (SBCE) on cost and lead time. Models are developed and treated using a system dynamics (SD) approach. We assign a hypothetical upfront investment for SBCE and compare its effects on  total cost and lead time of the development process. From the research, it is found that the total cost of PD is reduced almost by half-although the front loading is higher in order to encompass multiple design alternatives. The total product lead time is reduced by almost 20 %. The model reveals the critical time for improvement of the PD process. We use SD tool (e.g., STELLA) for simulation and visualization of the complex PD model, using SBCE as one of several strategies to frontload activities in the NPD process.     

Lot sizing in capacitated production planning and control systems

Current production planning and control (PPC) systems often separate material requirements from capacity planning. As a result, practitioners often complain about the infeasibility of production schedules regarding capacity, which causes long and unpredictable lead times and poor customers service. This paper describes a hierarchically structured PPC system that explicitly considers production capacity at each stage of the planning process. The impact of the certainty of demand data on the integration of lot sizing and sequencing decisions is discussed. A decision model for lot sizing applicable to changing demand data is proposed. It distinguishes between resources that are critical or uncritical with respect to batching decisions. Several currently available solution procedures are discussed and compared that support lot sizing decisions in multi-level production systems subject to multiple capacity constraints, setup times and dynamic demand rates.     

Framework on robotic percussive riveting for aircraft assembly automation

Presented in this paper is a framework for the implementation of a robotic percussive riveting system, a new robot application for aircraft assembly. It is shown here that a successful robot application to the automation of a process requires in-depth research of the process and the interaction with the robot. For this purpose, a process planning-driven approach is proposed to guide a robot application research.Atypical process planning will involve a list of
key considerations including: process sequence, process parameters, process tooling, and process control. Through this list, a number of key research issues are identified for robotic percussive riveting, such as rivet pattern planning,rivet time determination, rivet tooling design and rivet insertion control. The detailed research on these issues has effectively created know-how for the successful implementation of our robotic percussive riveting system.     

Wind turbine fault detection based on SCADA data analysis using ANN

Wind energy is one of the fast growing sources of power production currently, and there is a great demand to reduce the cost of operation and maintenance. Most wind farms have installed supervisory control and data acquisition(SCADA) systems for system control and logging data. However, the collected data are not used effectively. This paper proposes a fault detection method for main bearing wind turbine based on existing SCADA data using an artificial neural network(ANN). The ANN model for the normal behavior is established, and the difference between theoretical and actual values of the parameters is then calculated. Thus the early stage of main bearing fault can be identified to let the operator have sufficient time to make more informed decisions for maintenance.     

Current status,enablersand barriers of implementing cellular manufacturing system in Indian industries

The cellular manufacturing (CM) has been proved as a well-known manufacturing strategy that helps to improve manufacturing efficiency and productivity by
utilizing the philosophy of group technology. Large number of papers has been published in the area of design issues of CM system. Unfortunately, the issues related to acceptability of CM in Indian industries are typically not examined rigorously as technical issues. This paper presents the results of a survey carried out to find the status, enabler and barrier of implementing CM system in Indian industries.     

Product portfolio map:a visual tool for supporting product variant discovery and structuring

A fundamental criterion for reusing and continuously improving knowledge in product development is ensuring that the knowledge is explicit and visual.This paper is based on the situation of an engineer-to-order(ETO) manufacturing company,where historically grown product variety and related knowledge are diffuse(tacit).Consequently,several resources are used in(re)developing derivatives of previous products rather than innovating new ones.To establish a more competitive configure-to-order(CTO) product strategy,product knowledge needs to be revealed,systemized,and structured,and thus made explicit.Hence,product-specific knowledge and product variants have been analyzed and subsequently mapped at architectural,functional,and physical levels in one unified map and tested in the form of a proof-of-concept(POC)demonstrator with the introduced SME company.The result is a product portfolio map that forms a base for defining a systemized,transparent,unified product variant overview,which can be used as a basis for implementing a cross-variant product architecture and supporting knowledge-based approaches.     

Analysis of production planning and control (PPC) systems as an efficient combination of information activities

Production planning and control (PPC) systems with their planning structures, submodules and the information and data processing show similarities with the structures of multistage multi-product manufacturing. So, here the attempt is being made on the basis of the activity analysis to integrate the information characteristics of goods involved in production with regard to the requirements of production planning into the inputoutput relationships and to represent them in the form of so-called informational production functions. Based on the formulation of information activities efficiency criteria are developed, which allow to evaluate the data processing in PPC-modules and thus to eliminate inefficient activities. A concrete application to dynamic lot sizing demonstrates the procedure.     

基于OPT的生产作业计划与控制系统设计

建立符合我国企业实际情况的生产作业计划与控制系统是我国企业现代化改造和适应新的生产方式的主要问题之一。论述了建立生产作业计划与控制系统模型的基本方法,以最优化生产技术（ＯＰＴ）的基本原理为基础,结合我国企业的实际情况,对现代制造系统生产作业计划与控制系统的编制方法进行了探讨和开发应用。     

Integration of production planning,project management and logistics systems for supply chain management

The objective of this research was to develop an integrated framework to handle application modules in enterprise resource planning (ERP) and supply chain management (SCM) systems that traditionally needs to be interfaced on a case-by-case basis. This paper presents a framework integrating various modules in both systems, for planning, control and execution of materials, resources and operations. The framework enables planning and execution over a range of areas, from flow to project-based manufacturing and distribution from suppliers to customers. This document presents the conceptual framework development along with algorithms for scheduling paths, and illustrated numerical examples in the supply chain environment. The numerical evaluation of scheduling paths and planning of components, in the integrated networks, shows that the developed framework could cater for ERP/SCM application modules. The framework also facilitates simultaneous planning of many components, and eliminates the need for separate modules in ERPSCM systems. It enhances planning, control and execution, and simplifies the vendor follow-up system by integrating supplier components into the integrated network. The framework therefore becomes a new production planning (PP) module in integrated ERP/SCM systems and can provide links to other manufacturing philosophies, such as just-in-time (JIT).     

A review of production planning and control: the applicability of key concepts to the make-to-order industry

The paper reviews ‘classic approaches’ to Production Planning and Control (PPC) such as Kanban, Manufacturing Resource Planning (MRP II) and Theory of Constrains (TOC), and elaborates upon the emergence of techniques such as Workload Control (WLC), Constant Work In Process (CONWIP), Paired cell Overlapping Loops of Cards with Authorization (POLCA) and web- or e-based Supply Chain Management (SCM) solutions. A critical assessment of the approaches from the point of view of various sectors of the Make-To-Order (MTO) Industry is presented. The paper considers factors such as the importance of the customer enquiry stage, company size, degree of customization and shop floor configuration and shows them to play a large role in the applicability of planning and control concepts. The paper heightens the awareness of researchers and practitioners to the PPC options, aids managerial system selection decision-making, and highlights the importance of a clear implementation strategy. WLC emerges as the most effective Job Shop solution; whilst for other configurations there are several alternatives depending on individual company characteristics and objectives. The paper outlines key areas for future research, including the need for empirical research into the use of Workload Control in small and medium sized MTO companies.     

Optimal machining conditions for turning Ti-6Al-4V using response surface methodology

Machining titanium is one of ever-increasing magnitude problems due to its characteristics such as low thermal conductivity, modulus of elasticity and work
hardening. The efficient titanium alloy machining involves a proper selection of process parameters to minimize the tangential force (F_z) and surface roughness (R_a). In the present work, the performance of PVD/TiAlN coated carbide inserts was investigated using response surface methodology (RSM) for turning Ti-6Al-4V. The effects of process parameters such as speed (v), feed (f), depth of cut (d) and back rake angle (γ_y) on F_z and R_a were investigated.
The experimental plan used for four factors and three levels was designed based on face centered, central composite design (CCD). The experimental results indicated that F_z increased with the increase in d, f and decreased with the increase in v and γ_y, whereas Ra decreased with the increase in v and γ_y, and increased with d and v. The goodness of fit of the regression equations and model fits (R ²) for F_z and R_a were found to be 0.968 and 0.970, which demonstrated that it was an effective model. A confirmation test was also conducted in order to verify the correctness of the model.     

Experimental investigation on the effects of process parameters of GMAW and transient thermal analysis of AISI321 steel

Gas metal arc welding (GMAW) develops an arc by controlling the metal from the wire rod and the input process parameters. The deposited metal forms a weld bead and themechanical properties depend upon the quality of the weld bead. Proper control of the process parameters which affect the bead geometry, the microstructures of the weldments and the mechanical properties like hardness, is necessary. This experimental study aims at developing mathematical models for bead height (HB), bead width (WB) and bead penetration (PB) and investigating the effects of four process parameters
viz: welding voltage, welding speed, wire feed rate and gas flow rate on bead geometry, hardness and microstructure of AISI321 steel with 10 mm thickness. The transient thermal analysis shows temperature and residual stress distributions at different conduction and convection conditions.     

Towards zero-defect manufacturing (ZDM)—a data mining approach

The quality of a product is dependent on both facilities/equipment and manufacturing processes. Any error or disorder in facilities and processes can cause a catastrophic failure. To avoid such failures, a zero- defect manufacturing (ZDM) system is necessary in order to increase the reliability and safety of manufacturing systems and reach zero-defect quality of products. One of the major challenges for ZDM is the analysis of massive raw datasets. This type of analysis needs an automated and self-organized decision making system. Data mining (DM) is an effective methodology for discovering interesting knowledge within a huge datasets. It plays an important role in developing a ZDM system. The paper presents a general framework of ZDM and explains how to apply DM approaches to manufacture the products with zero-defect. This paper also discusses 3 ongoing projects demonstrating the practice of using DM approaches for reaching the goal of ZDM.     

Multi-agent systems applications in manufacturing systems and supply chain management: a review paper

This paper offers a review of the development and use of multi-agent modelling techniques and simulations in the context of manufacturing systems and supply chain management (SCM). The objective of the paper is twofold. First, it presents a comprehensive literature review of current multi-agent systems (MAS) research applications in the field of manufacturing systems and SCM. Second, it aims to identify and evaluate some key issues involved in using MAS methods to model and simulate manufacturing systems. A variety of different MAS applications are reviewed in three different classified research areas: production design and development, production planning and control, and SCM. In presenting a detailed taxonomy of MAS applications, the paper describes MAS application domains from five different perspectives. The review suggests the MAS approach represents a feasible framework for designing and analysing real-time manufacturing operations, since the approach is capable of modelling different levels of agent behaviour and dynamical interactions. The paper also highlights a number of key issues which have to be taken into account in attempting to design MAS-based research paradigms for future applications in manufacturing systems.     

Study of structural,electrical and optical properties of vanadium oxide condensed films deposited by spray pyrolysis technique

Vanadium oxides condensed films are prepared on glass substrates, using spray pyrolysis (SP) technique.The effects of substrate temperature, vanadium concentration in initial solution and the solution spray rate on the nano-structural, electrical, and optical properties of deposited films were investigated. Characterizations of the samples were performed using X-ray diffraction (XRD),scanning electron microscopy (SEM), and UV-Vis spectroscopy methods. The type and concentration of the charge carriers were determined and measured by Hall effect experiment. XRD patterns showed that the prepared films had polycrystalline structure, mostly tetragonal β-V₂O₅ and V₄O₉ phases with the preferred orientation along (200) direction. The Hall effect experiment revealed that all samples were n-type, except the ones deposited at substrate temperatures Tsub = 300 ℃ and Tsub = 450 ℃, vanadium concentration 0.1 mol/L and solution spray rate 10 mL/min.The charge carrier concentrations obtained were in the range 10¹⁶–10¹⁸ cm^-3. The lowest sheet resistance (R_s) was obtained for the samples prepared at T_sub = 450 ℃, vanadium concentration 0.05 mol/L and solution spray rate 10 mL/min. It was also found that the optical transparency of the samples changed from 20% to 75% and the optical band gap of the samples was from 2.22 eV to 2.58 eV, depending on the deposition conditions.     

Microwave-assisted rapid synthesis of alumina nanoparticles using tea,coffee and triphala extracts

Alumina nanoparticles (AlNP) were synthesized from aluminium nitrate using extracts of tea, coffee and triphala—a well known herbal plant as well as a nontoxic and eco—friendly green material. The synthesis was carried out taking 1:4 ratio of metal salt and these extracts under microwave irradiations at 540 W, which gave better yield of nanoparticles. Water was taken as solvent medium. The formations of AlNP were initially monitored by the colour changes occurring in the reaction mixture during the incubation period. As synthesized nanoparticles were characterized by scanning electron microscope (SEM),
UV–Visible (UV–Vis) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The AlNP were found to be spherical in shape in case of tea and coffee extracts with a size of 50–200 nm and to be oval shaped in case of triphala extract with an average size of 200–400 nm. The formation of AlNP with the microwave-assistance using these plant extracts has proved to be very faster than any other methods. In addition, excellent reproducibility of these nanoparticles, without the use of any additional capping agent or stabilizer will have great advantages in comparison with microbial synthesis, avoiding all the tedious and hygienic complications.     

Virtual simulation of production line for ergonomics evaluation

To avoid ergonomic problems in the early planning stages of a production line and achieve more satisfactory planning and design, ergonomic simulation is
particularly important in digital production line planning. An ergonomics analysis method is presented by using two theories: Ovako working posture analysis system (OWAS) and Burandt-Schultetus hand-arm force analysis (BSHA). The processes of ergonomics analysis and simulation are discussed based on a platform of process simulation and process designer. As an example, the paper shows how ergonomics problems are considered in production line planning to make a better choice between different production line planning schemes.