Lifecycle Of Manufacturing Systems Research Articles

From automation toward integration of process planning: a state-of-the-art review

The two main objective functions for designing the manufacturing system are, improving the manufacturing system's productivity and production quality. Process planning is an integral part of manufacturing system design. In this work, the study of process plan evolution over the period has been reviewed, keeping in mind the design objectives. Based on the technological advancements, the process plan evolution has been classified into two periods. The first evolution relates to automation, in which efforts are made to automate the manual activities of conventional process plans, which leads to the development of Computer-Aided Process Planning (CAPP). As long as the systems are deterministic with fixed structures and capabilities, CAPP is a good solution. Due to the uncertainty in the market for product demand, the new manufacturing systems are becoming more and more dynamic to handle the product variety demand. In that case, just automation is not enough to achieve the objective functions of system design. Designers have to consider the integration of the manufacturing system life cycle. So the second evolution of the process plan relates to, the consideration of performance indicators defined due to the system integration. For the second evolution, the literature review of the reconfigurable process plan (RPP) is performed considering both automation and integration of the system.

Mapping the path to certification of metal laser powder bed fusion for aerospace applications

Purpose The purpose of this paper is to identify and define the certification lifecycle of laser powder bed fusion for aerospace applications from equipment acquisition and installation to production, part acceptance and continuous improvement activities. Design/methodology/approach A top–down systems engineering approach is performed consisting of concept development, requirements engineering and systems architecting. This approach is taken from the perspective of a production organization. Findings A certification roadmap is proposed that references industry requirements at the relevant phases of the roadmap. Each phase of the roadmap acts as a decision gate for progression to the next. Originality/value Qualification and certification of metal laser powder bed fusion is currently a challenge within the aerospace industry. From an aerospace point of view, the qualification and certification of this relatively new manufacturing process should not have to be any different from traditional manufacturing processes, although with extensive quality control and regulatory oversight. This paper proposes a means for fulfilling these requirements chronologically and provides guidance on ensuring such quality control throughout the manufacturing system lifecycle. This roadmap provides insight into the qualification and certification of laser powder bed fusion for aerospace applications and provides value for future industrial feasibility studies.

Knowledge-based Estimation of Maintenance Time for Complex Engineered-to-Order Products Based on KPIs Monitoring: A PSS Approach

Maintenance is the most common product-oriented Product Service System (PSS) offering, as well as a core activity of the manufacturing system lifecycle, since it accounts for as much as 60 to 70% of its total costs. Commonly, in the Small Medium Enterprises (SMEs), the maintenance activities of customised engineering-to-order (ETO) products highly depend on the experience of engineers and shop-floor experts, without considering specific tools and algorithms that can capture the knowledge and reuse it in an efficient way. Moreover, the estimation of the maintenance time for a new maintenance project, which is among the main offerings in the maintenance, is solely based on the engineer's experience and knowledge. Aiming to support the knowledge capturing and its reuse in the maintenance activities, as well as to improve the performance of the provided maintenance PSS, the present work proposes a methodology for knowledge-based estimation of maintenance time based on Key Performance Indicators (KPI) monitoring. Data captured through the KPIs monitoring tool were collected in a knowledge repository, and were processed using a Case-Based Reasoning (CBR) technique, estimating the required maintenance time. A validation of the proposed methodology was performed based on real-life data from a mold-making European Small Medium Enterprise (SME). Preliminary results indicated a significant reduction in the number of iterations between customers and the engineering department, compared to the traditional approach followed by the company, and improved accuracy of maintenance time estimation, which led to increased customer satisfaction.

A Case for Assisting ‘Product Family’ Manufacturing System Designers

Manufacturing system design is a complex and demanding activity and the system designer has to take many factors into consideration during the development process including the demand and technological requirements of the products or product families. Central to this activity is the synthesis decision making process, during which the designer defines the elements that will make up the manufacturing system. This research identifies in the decision making process a critical activity and contributes a phenomena that can be used by a framework to support designers to address complex issues such as changeability and the evolution of products over the manufacturing system life-cycle.

A method for comparing flexibility performance for the lifecycle of manufacturing systems under capacity planning constraints

The objective of this work is to describe a method for comparing the flexibility performance of manufacturing systems, in an uncertain environment, under lifecycle considerations and capacity planning constraints. The manufacturing systems costs are estimated over a time horizon and for a large variety of possible market scenarios. In order for the lifecycle cost values to be comparable among different systems, their values are calculated with the use of a special purpose algorithm. Statistical analysis of the estimated cost values is then employed for assessing the flexibility of each manufacturing system. The method is applied in an industrial case for checking, also from a flexibility point of view, the investment on a production system, using real life industrial data.

Automatic transformation of logic models within engineering of embedded mechatronical units

Engineering of manufacturing systems is one of the most important aspects within the life cycle of manufacturing systems in terms of cost. Within the engineering process, several engineering activities are executed by different experts commonly using specific tools for the design of the different parts of the system. To reduce engineering costs beneath, two main approaches arise. The first is based on the use of libraries of mechatronical units as reusable artifacts. In this case, manufacturing systems are represented as a hierarchy of mechatronic units. The second option is to achieve the seamless connection of the different engineering tools exploiting a common data exchange format. This latter approach allows avoiding both double engineering and faults within the engineering process. Within this paper, a novel approach combining both options is proposed, and its effects are analyzed through an example. It considers the application of mechatronical units within the engineering process of manufacturing systems as well as a common data exchange format for the logic information required for designing the control system within the engineering of manufacturing systems. The latter provides a data exchange format for the overall engineering process, including not only model information exchange but also its embedding. This paper discusses the benefits of the data exchange format for logic models in detail.

DESYMA: assessing flexibility for the lifecycle of manufacturing systems

The objective of this work is to describe a method of assessing the flexibility of a manufacturing system, in an uncertain market environment, under lifecycle considerations. The flexibility of a manufacturing system is determined by statistical analysis of the discounted cash flow (DCF) estimates of the manufacturing system's lifecycle cost, over a time horizon and for a large variety of market scenarios. The system's lifecycle cost is calculated at a minimum level with the help of a specially developed algorithm. The method is used in a test case for investing in a production system, using real-life data derived from the automotive industry.

Flexible and reconfigurable manufacturing systems paradigms

Reconfigurable Manufacturing System (RMS) is a new manufacturing systems paradigm that aims at achieving cost-effective and rapid system changes, as needed and when needed, by incorporating principles of modularity, integrability, flexibility, scalability, convertibility, and diagnosability. RMS promises customized flexibility on demand in a short time, while Flexible Manufacturing Systems (FMSs) provides generalized flexibility designed for the anticipated variations and built-in a priori. The characteristics of the two paradigms are outlined and compared. The concept of manufacturing system life cycle is presented. The main types of flexibility in manufacturing systems are discussed and contrasted with the various reconfiguration aspects including hard (physical) and soft (logical) reconfiguration. The types of changeability and transformability of manufacturing systems, their components as well as factories, are presented along with their enablers and compared with flexibility and reconfigurability. The importance of having harmonized human-machine manufacturing systems is highlighted and the role of people in the various manufacturing paradigms and how this varies in pursuit of productivity are illustrated. Finally, the industrial and research challenges presented by these manufacturing paradigms are discussed.

生産システムのためのリアルワールドとシミュレーションワールドの結合 : 第二報 ソフト結線システムと設備シミュレータ(S60-1 生産システムの新展開(1),S60 生産システムの新展開)

Our objective is to establish a simulation system that can be used easily throughout the manufacturing system life cycle. Therefore, we have been developing the manufacturing simulation system by using distributed simulation architecture, HLA. However, it is too difficult to apply the simulation system to the implementation stage of real factory line, because the simulation language is not executable on the real equipment. In this paper, we describe a method and a system for introducing the real equipment or its emulator into the manufacturing simulation. As a result, the user can simulate the motion etc. of the machine with the dedicated tools of the equipment.

4201 生産システムのライフサイクルにおけるエンジニアリング活動の効率化

Manufacturing industries are facing borderless mega competitions to survive in a global market today. In order to defeat competitors, cost reduction and quality improvement should be done as a matter of course. But the most important point is when to market. As soon as customers' needs are clear, manufacturers should develop new products, install manufacturing systems, and put the products into a global market right on time. Such agility is indispensable for all manufacturers. To realize agility new engineering methods, such as concurrent Engineering, Simultaneous Engineering, and Virtual Enterprise, has been adopted and various information technologies, such as CAD, CAM, CAE, network, database, etc., are installed to support manufacturing system engineering activities through the manufacturing system life cycle, which covers designing, constructing, operating and recycling.

Strategic FMS design under uncertainty: A fuzzy set theory based model

Flexibility is assuming more and more relevance in the manufacturing strategy, because it allows to face the increasing uncertainty in which the firms are competing nowadays. In order to increase their strategic competitiveness, several firms in many industries are increasing their investment in Flexible Manufacturing Systems (FMS). In the first FMS design step the following decisions should be made: (a) flexibility level decision, i.e. how many kind of products the designing FMS has to produce; (b) size level decision, i.e. what is the aggregate volume the FMS can perform; (c) capacity definition decision, i.e. how many machines for each type have to be installed. These decisions are to be made under an uncertain design environment. The major uncertainty concerns the demand and the price for each product due to the market forecasts uncertainty, and the work-load characteristics (time and routing) of each product due to the product changes over the manufacturing system life cycle. The design objectives are the expected profit maximization and the investment risk minimization, trying to increase the flexibility level and to reduce the profits uncertainty. This paper proposes a fuzzy set theory multiple objectives model that is able to face the uncertainty in the design data determining the FMS configuration that optimizes the expected profits considering the entrepreneur risk propensity.

A formal methodology for information model level integration in CIM systems

Manufacturing systems are complex and involve multiple software applications, each containing an internal representation of the manufacturing system in the form of a database or data files. Each database is an instantiation of a data model which is developed as an abstract representation of the environment of the tool. The model therefore, defines an application's database and is influenced by how the users of an application view the system. These views are be influenced by where in the product or manufacturing system life cycle the software is used, what functional areas use the software, and the detail at which the system is modeled. Early attempts at integration focused of overcoming the communications difficulties between computers. This paper presents a framework for integrating CIM software applications by developing a unified system view. In effect developing a common language into which each tool can map it's representation. Finding the common data becomes a function then of identifying which data overlaps. This view identifies software applications which contain duplicate and possibly inconsistent data. These overlaps of data are then characterized by formal properties which can be used to maintain consistency. These formal properties establish precedence and whether data is a constraint, an exact value or an estimated value. Duplicate data can be used to establish constraints that one software system places on other systems. Duplicate data can also be shared between systems.