Sebastian Thiede

An environmental perspective on Lean Production

To cope with the challenges of the business environment companies strive to reorganize their production with certain principles and methods in the sense of Lean Production. Whereas these measures are naturally primarily motivated by classical production objectives like cost, time, quality or flexibility, companies also face diverse originally environmentally driven challenges which also incorporate a strong economic relevance. However, methods of Lean Production are not necessarily environmentally friendly. Thus, there may exist certain conflicts in goals for companies. Against this background, this paper presents an analysis of the coherences and interdependencies between Lean Production and ecologically oriented variables specifically energy consumption. Besides the discussion of principles and methods regarding their environmental influence, a simulation approach is used to analyze the specific effects of certain Lean Production measures on economic as well as environmental variables of a manufacturing line.

An implemented framework to estimate manufacturing-related energy consumption in product design

Manufacturing systems energy efficiency and the embodied energy of products are highly commented topics nowadays. So far, despite their interrelated nature, they have unfortunately been considered to be quite different from each other. Consequently, on one hand, product design remains as an unrecognised influence on the energy consumption of a manufacturing system, and on the other hand, manufacturing energy efficiency is unrealistically estimated in the calculation of product embodied energy. The present article integrates the existing literature on manufacturing energy consumption models and sets up a conceptual framework to assess the energy consumption of manufacturing systems from a product design perspective. This framework was implemented in a prototype software workflow, which was proven to generate interesting results for ecodesi gn and cleaner production initiatives. It helps in deriving realistic energy consumption values that can be linked to concrete product or process parameters, and therefore allows the improvement of product manufacturing energy efficiency at both design and manufacturing stages.

An Extended Energy Value Stream Approach Applied on the Electronics Industry

In today’s manufacturing companies lean production systems are widely established in order to address the traditional production objectives such as quality, cost, time and flexibility. Beyond those objectives, objectives such as energy consumption and related CO2 emissions gained relevance due to rising energy costs and environmental concerns. Existing energy value stream methods allow the consideration of traditional and energy related variables. However, current approaches only take the energy consumptions of the actual manufacturing process and set-up times into account neglecting non-productive operational states and technical building services related consumption. Therefore, an extended energy value stream approach will be presented that provides the necessary degree of transparency to enable improvements of the energy value stream of a product considering also the influence of product design parameters.

State of Research and an innovative Approach for simulating Energy Flows of Manufacturing Systems

The paper addresses the issue of energy efficiency as an important topic in sustainability in manufacturing. Against the background of a necessary holistic system understanding and derived research demand, an innovative energy flow oriented manufacturing system simulation approach is presented. Besides the description of the conceptual approach, the applicability and the potentials of usage are shown in two different case studies.

Lean Production System Design from the Perspective of the Viable System Model

Within the design stage of lean production systems, decisions regarding production system design parameters in terms of lean methods have to be taken. While the economic effects of lean methods have been described in practice, there is still a demand for a scientific basis that allows to explain the mode of action of lean methods. The Viable System Model (VSM) supports the analysis of mechanisms within companies, and provides invariant structures for ensuring the viability of organizations. Based on the findings of the VSM, the connection between the lean production system approach and the cybernetic VSM approach are investigated and lean methods are described in terms of attenuating and amplifying variety.

Dynamic life cycle costing based on lifetime prediction

Reliable prediction of total product life cycle costs is crucial for the life cycle management of products. These costs are predominantly dictated by the actual operational behaviour of the products lifetime, and cannot be sufficiently determined through deterministic calculations due to the stochastic and the dynamic nature of the problem. This is specifically true when considering running systems with unknown lifetime and operation parameters. Against this background, the paper presents a dynamic methodology for predicting life cycle costs based on product failure mechanisms, their associated critical lifetime prediction parameters and optional maintenance strategies to enable decision support for product design and use phase strategies.

Framework for Integrated Analysis of Production Systems

Production companies act in increasingly complex and dynamic environments. Facing numerous influencing and closely interconnected factors within production systems, companies are forced to cope with economic and to an increasing degree with ecological objective criteria in order to meet market and legal demands. This leads to complex decision situations regarding planning, operation, and optimization efforts of production systems. This paper presents an integrated framework for production system analysis that allows to analyze the interrelations between economic and ecological factors in the context of production system optimization.

Life Cycle Assessment of 3D Printed Products in a Distributed Manufacturing System

Summary Motivated by the rising costs of doing business overseas and the rise and implementation of digital technologies in production, new strategies are being explored to bring production and demand closer. While concepts like cloud computing, internet of things, and digital manufacturing increasingly gain relevance within the production activities of manufacturing companies, significant advances in three-dimensional (3D) printing technologies offer the possibility for companies to accelerate product development and to consider new supply chain models. Under this production scheme, material supply chains are redefined and energy consumption hotspots are relocated throughout the life cycle of a product. This implies a diversification of energy mixes and raw material sources that poses a risk of shifting problems between life cycle phases and areas of protection. This study compares a conventional mass scale centralized manufacturing system against a 3D printing-supported distributed manufacturing system on the basis of the production of one frame for eyeglasses using the life cycle assessment methodology. The study indicates clearly that the optimization potential is concentrated mainly in the energy consumption at the unit process level and exposes a close link to the printing material employed.

An integrated approach for improving energy efficiency of manufacturing process chains

The rising energy prices and increasingly imposing regulations have drawn attention for improving the energy efficiency of manufacturing processes. Over the past decade, different approaches have been developed to target from individual unit processes to entire manufacturing systems. However, each model or approach has limitations in terms of the efficiency improvement. Thus, an integrated approach is proposed to overcome these limitations combining unit process energy consumption models with production system simulation. The outcome potentially leads to a more energy-efficient production and process planning, which considers the dynamics of individual processes as well as the entire system. Two case studies are presented to demonstrate the approach and its benefits.

Dynamic Total Cost of Ownership (TCO) Calculation of Injection Moulding Machines

As an extension to the investment oriented business perspectives, the evaluation and the active usage of Total Cost of Ownership (TCO) concepts are significantly gaining importance in manufacturing companies. TCO subsumes all cost portions that occur for the operator of a machine. While essential shares of the TCO (energy and maintenance) cannot be determined by static calculations, a method for a dynamic calculation of the TCO of production machines is presented. It allows a realistic calculation of the TCO by taking into account individual machine characteristics and behaviour as well as uncertainties over the entire period of ownership.