Although Lean manufacturing techniques are not yet in place in every shop floor production, the so-called Smart Factory with the very promising German-coined label "Industry 4.0" is already making its tour. While the Toyota Production System (TPS) has shown to be the most performant manufacturing system, the Industry 4.0 initiative is still in the scoping phase with the demanding goal to become a highly integrated cyber production system. The partial and often limited knowledge about Lean production leads to distorted ideas that the two approaches are incompatible. In order to eradicate wrong statements, this paper tries to explain what Lean really is and how it has to be considered in the context of the Industry 4.0 initiative. Further, it discusses the existing contradiction within the Industry 4.0 goals regarding manufacturing performance and break-even point. KeywordsToyota, Production System, Lean, Industry 4.0, Smart Factory, Performance PrefaceThis paper bases on the well received presentation "From Lean to Industry 4.0: An Evolution?-From a Visionary Idea to Realistic Understanding" held at -new products and new services -new business models -internet of things (IOT) -big data -self-scheduled maintenance -virtual reality/augmented reality -fully automated production This paper does not pretend to be a comprehensive scientific essay about Lean or Industry 4.0; it rather gives some ideas and concepts about Lean and the place Industry 4.0 might take within Lean. It is neither a position paper defending Lean manufacturing nor an essay promoting the Industry 4.0 initiative. It is just an essay having the intention to clarify basic concepts to eliminate wrong ideas about what Lean is in order to facilitate the correct relationship between the Industry 4.0 initiative right from the beginning. In the following, we will focus on the manufacturing performance dimension of the Industry 4.0 initiative. IntroductionThe term Industry 4.0 has been coined at the 2011 Hannover Fair, a concept better known as the "Smart Factory". The 4.0 makes reference to be a forth industrial revolution to come. The first industrial revolution is generally considered to be the steam machine which made the steam power exploitable opening the industry age. The second industrial revolution is generally seen as the discovery, or better the application, of electricity and how to use it, namely allowing automotive mass production. The third industrial revolution is generally linked to the computer and the possibility of data processing for computer integrated manufacturing (CIM), leading to the present era of information technology. These commonly used definitions of industrial revolutions were made retrospectively, i.e. are ex-post rationalizations. All these revolutions were linked to inventions based on break-through scientific discoveries (Watt, Tesla, von Neuman) with their first application opening new industries. Note that even real revolutionary inventions, such as Marconi's wireless telecommunication (Nobel prize in 1909) sta...

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Personal consulting experience has been showing that even many proven managers responsible for Lean Six Sigma Operational Excellence (OPEX) techniques have not fully understood the profound and comprehensive significance of Lean. Apart from the idealized interpretation of Lean boiled down to the limited concepts of Muda and Kaizen, the classical "temple" representation of the Toyota Production System (TPS) often leads to the interpretation that Lean is a toolbox from which one can select supposedly independent tools. By picking just some tools, however, the full potential of the TPS certainly cannot be exploited and-in the worst case-it may even cause production disruption. This essay criticizes the wide-spread ultra-simplification of concepts and, as a consequence, the distorted interpretation leads to an inappropriate use of the Lean tools. It presents two additional representations of the classical TPS temple model stressing the intrinsic systemic effects as well as the underlying theory concepts of the TPS to allow a flawless Just-inTime (JIT) production. In fact, the original TPS is not a toolbox, but a comprehensive synergic tool system.

Respecting the on-time delivery (OTD) for manufacturing orders is mandatory. However, for non-JIT Batch & Queue Push-manufacturing systems, the compliance of OTD is not intrinsically guaranteed. As an OTD related manufacturing theory is largely missing it is crucial to understand and formalize the necessary conditions of OTD compliance for complex production environments for maximum exploitation of the production capacity. This paper evaluates the conditions of post-optimality while being OTD compliant for production systems, which are characterized by stochastic order rate and a deterministic product-mix. Instead of applying discrete event simulation to explore the real case-by-case order scheduling optimization for OTD compliance, a Cartesian approach is followed. This enables to define theoretically the solution space of order backlog for OTD, which contributes to developing further manufacturing theory. At the base stands the recently defined new concept of virtual manufacturing elasticity by reducing lead-time to increase virtually production capacity. The result has led to defining additional two corollaries to the OTD theorem, which sets up basic OTD theory. Apart from defining the post-optimal requirements to guarantee for orders at least a weak solution for OTD compliance, this paper reveals that for a deterministic product-mix a non-ergodic order arrival rate can be rescheduled into an ergodic order input rate to the shopfloor if the virtual elasticity ∆T is large enough, hence the importance of having fast and flexible production lines. How to cite this paper: Rüttimann, B.G. and Stöckli, M.T. (2021) Exploiting Virtual Elasticity of Manufacturing Systems to Respect OTD-Part 2: Post-Optimality Conditions for the Cases of Ergodic and Non-Ergodic Order Rate with Deterministic Product-Mix.

Lean Six Sigma tools have been increasingly employed also in the service industry, however with different success as field studies have shown. The reason not only has to be attributed to a poor Change Management, but can also be attributed to the intrinsic characteristics of the Lean techniques, which have been tailored to sustain a stable customer-takted pull-manufacturing principle. An office workplace shows significant differences to a procedural shop floor environment, as it comprises both, procedural and relational processes. The office environment, therefore, cannot be described by a purely transactional shop floor model-it necessitates a separate model, with a differenciated approach, which covers the procedural as well as the relational aspects of office tasks. Also the different characteristics of the transaction object as well as the operation transformation and process governance do not allow an un-adapted application of Toyota's comprehensive Lean toolset. The approach of Lean for the office environment needs a reinterpretation of the Lean logic and TPS Lean tools for the procedural part as well. Therefore, different and adapted approaches and tools are clearly necessary. The paper shows the objectives and principles of Lean and why Lean manufacturing is also interesting to be applied in the office environment. The differences between office and production jobs are detailed and introduce the problem of lean application in the office. The particular characteristics of the office environment are discussed and enable to enter into the Relational Office Model. Furthermore, we explain the paradigm shift which is necessary to take full benefit of the Lean approach in the office environment, however without presenting the reinterpreted office Lean toolset due to space reasons. This will be the topic of a next paper.