2013 XXIV International Conference on Information, Communication and Automation Technologies (ICAT) October 30 – November 01, 2013, Sarajevo, Bosnia and Herzegovina 978-1-4799-0431-0/13/$31.00 ©2013 IEEE Dynamic cycle times for adaptive manufacturing control in automotive flow shops R. Lepratti 2 , U. Berger 3 , 1 Corporate Technology, Siemens AG, Munich 2 Sector Industry, Siemens AG, Nuremberg T. Creutznacher 1, 3 , S. Minhas 3 3 Brandenburg University of Technology Cottbus, Cottbus Abstract—The automotive industry has to deal with an increasing complexity of production processes and various kinds of disturbances along the supply chain. This requires a higher level of flexibility through an intelligent production planning from the engineering phase. Today’s manufacturing flexibility is mostly provided during the operational phase (so-called run- time) by methodologies for order re-scheduling and re- sequencing. The focus of this paper is a novel concept, which adds the intelligent production planning to these methodologies and uses the synergies of the holistic system. This approach enables flexible automated manufacturing processes by the dynamic use of machine capabilities during run-time. The paper shows in details how the adaption of operating speeds both in manufacturing and material handling processes leads to dynamic cycle times with maximized Key Performance Indicators (KPIs). This concept is based on so-called production variants defined and validated during the engineering phase. First results show stability and good response of the test system. Keywords—manufacturing flexibility; dynamic cycle times; manufacturing IT; production assistance; PLM; MES I. INTRODUCTION In the automotive industry car makers with high volume and low variance production are organized in a flow shop [1]. The production and material flow are increasingly getting complex and therefore more sensitive to disturbances like missing material supply or delivery delays. This increasing complexity is a result of just-in-time (JIT) and just-in- sequence (JIS) processes as well as of influences of lean management, mass customization and faster product lifecycles, e.g. logistics and intra-logistics. In order to react to these disturbances, production needs to be more flexible and able to implement strategies on short notice. Flexible adaptations during the run-time in automotive push systems are mainly driven by three IT levels. First, the Enterprise Resource Planning (ERP) supports the long-term commercial planning and (re-)scheduling of resources, e.g., machines, personnel and material. Typically the ERP is supported by an Advanced Planning and Scheduling (APS) system. Second, the Manufacturing Execution System (MES) is responsible for detailed production scheduling, execution and control, maps the current state of production and links the ERP with the shop floor. Third, the shop floor contains the machine automation with several controllers, sensors and actuators. Controllers build a hierarchic structure of programmable logic controllers (PLCs), robot control units (RCs) or numeric control units (CNCs) that serves the production execution. The focus of this paper is to present a concept for flexible automated manufacturing processes provided by the dynamic use of machine capabilities during run-time. The following chapters are structured as follows: Related work regarding flexibility of manufacturing processes is reviewed in Chapter II. Chapter III introduces the concept and preconditions for dynamic cycle times, which are integrated into production- related IT systems via production variants (Chapter IV). Chapter V describes a test environment, whereas Chapter VI finally provides a short summary and outlook. II. MANUFACTURING FLEXIBILITY There is no clear definition for manufacturing flexibility. [2] describes flexibility as the characteristic of production systems to adapt fast and with minimal effort to changed basic conditions in a predetermined area. Therefore manufacturing flexibility is distinguished to versatile and reconfigurable systems. However, [3] is a little more precise and defines flexibility as “the ability to change or react with little penalty in time effort, cost or performance”, whereas [4] characterizes it as “the ability of the firm to manage production resources and uncertainty to meet customer requests”. The categorization of manufacturing flexibility is likewise inconsistent. According to [5, 6] manufacturing flexibility is multidimensional and consists of the following five dimensions: uncertainty types (e.g., “timing of arrival of inputs or demand for the kind of products offered”), flexibility types, flexibility mechanisms, operational levels and flexibility measurements. However, [7] differs between subcategories of manufacturing flexibility from management view and [8] between eleven flexibility concepts in detail. The six manufacturing flexibility types based on [5, 6] are: • mix flexibility: “produce a number of different products at the same point in time” • volume flexibility: “(easily make) changes in the aggregate amount of production” • rerouting flexibility: “(change) the operating sequence through which the parts flow” • modification flexibility: “make functional changes in the product”