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Rijkswaterstaat (RWS), the executive branch of the Dutch Ministry of Infrastructure and Water Management, has announced that a significant number of ship locks in the Netherlands are due for renovation during the coming decades. The renovation of ship locks allows RWS to reconsider current existing preferences for lock design and to investigate options to develop a product platform for locks. This paper presents a method for the development of such a platform, based on the functions of a lock and the component alternatives to provide that function. By applying design structure matrix (DSM) modeling and value analysis methods, a ranked set of feasible lock configurations can be obtained that meets the specific requirements for a particular lock location while trading against the desired commonality in the family of locks. Preferred configuration attributes are to be incorporated in a product platform for locks to support RWS with the planned lock renovations.

A significant number of ship locks in the Netherlands are due for renovation during the coming decades. To achieve this, Rijkswaterstaat (RWS), the executive branch of the Dutch Ministry of Infrastructure and Water Management, is investigating the options to meet the specific requirements, while allowing the necessary variety in the configuration of locks. This paper presents a method for the development of a module-based product platform for locks, based on component types and their combinations. By combining different design structure matrix (DSM) modeling methods, possible modules of lock components are defined and assessed. These modules consist of lock components that have a high level of commonality and thus influence each other. Together, these modules form the basis for a product platform for locks, supporting RWS with the renovation of their portfolio.

The hybrid @g (Chi) formalism is suited to modeling, simulation and verification of hybrid systems. It integrates concepts from dynamics and control theory with concepts from computer science, in particular from process algebra and hybrid automata. In this paper, we first provide an overview of @g. Then, the @g formalism is related to other formalisms by means of translation schemes: a translation scheme from continuous-time PWA systems to @g, a translation scheme from discrete-time PWA systems to @g, and a translation scheme from hybrid automata to @g. In order to be able to use existing model checkers that use hybrid automata like input languages, we developed and implemented a translation scheme from a subset of @g to hybrid automata. To illustrate this approach, a case study has been performed: a water level monitor has been modeled using @g. Using the implemented translation scheme from @g to hybrid automata, we obtain a hybrid automata model for the water level monitor. From this model, code that can be used as input for the model checker PHAVer is generated.

A compositional interchange format for hybrid systems is defined in terms of an interchange automaton, allowing arbitrary differential algebraic equations, including fully implicit or switched DAEs, discrete, continuous and algebraic variables, that can be internal or external, urgency conditions, and operators for parallel composition, action hiding, variable hiding and urgent actions. Its compositional semantics is formally defined in terms of a hybrid transition system. This allows development of transformations to and from other formalisms that can be proven to preserve essential properties, and it allows a clear separation between the mathematical meaning of a model and implementation aspects such as algorithms used for solving differential algebraic equations.

The paper considers standard fluid models of multi-product multiple-server production systems where setup times are incurred whenever a server changes product. Concerned is the general approach to the problem of optimizing the long-run average cost per unit time that offers to first determine an optimal steady state (periodic) behavior and then to design a feedback scheduling protocol ensuring convergence to this behavior as time progresses. The second part of this program is treated and a systematic presentation of a novel approach to it is offered. This approach gives rise to protocols that are cyclic and distributed: the servers do not need information about the entire system state. Each of them proceeds basically from the local data concerning only the currently served queue, although a fixed finite number of one-bit notification signals should be exchanged between the servers during every cycle. The approach is illustrated by simple albeit instructive examples concerning polling systems, single server systems with processor sharing scheme, and the re-entrant two-server manufacturing network with non-negligible setup times introduced by Kumar and Seidman. For the last network considered in the analytical form, the optimal steady-state (periodic) behavior is first determined. Based on the desired steady state behavior and the presented theory, we designed simple distributed feedback switching control laws for all examples. These laws not only obtain the required behaviors but also make them globally attractive, irrespective of the system parameters and initial state.

An aggregate model of an order-picking workstation is proposed for an automated warehouse with a goods-to-men order-picking system. A key aspect of the model is that the various stochasticities that contribute to the workstation performance are not modelled in detail. Rather, these are aggregated into a single effective process time distribution, which is calculated from arrival and departure times of products at the workstation. Two model variants have been developed namely for workstations processing products and orders in first-come-first-serve (FCFS) and non-FCFS sequence. Both model variants have been validated using data obtained from an operating order-picking workstation. The use of aggregate models in practice is then elaborated.

By means of Ramadge–Wonham supervisory control theory, supervisory controllers (supervisors) can be synthesized instead of designing them manually. This chapter presents an application of supervisory control to a patient support system for MRI scanners. The design process of the controller from its requirements to its actual implementation on real hardware has been done according to the synthesis-based engineering paradigm. This paradigm integrates the model-based engineering and supervisory control paradigms. The design process is supported by a tool framework that is based on the Compositional Interchange Format for hybrid systems (CIF). An experiment conducted in the course of the case-study indicates that this design process improves the evolvability of the controller significantly.

The extension of timed formalisms to a hybrid setting with urgency, has been carried out in a rather straightforward manner, seemingly without difficulty. However, in this paper, we show that the combination of urgency with abstraction from continuous variables leads to undesired behavior. Abstraction from continuous variables ultimately leads to a timed system again, but with a much richer set of possible branching behaviors than a timed system that comprises only clocks. As it turns out, the formal definition of urgency, as defined for timed systems with clocks, does not fit our intuition of urgency anymore when applied to a timed system that is an abstraction of a hybrid system. Therefore, we propose to extend the formal semantics of timed and hybrid systems with guard trajectories. In this way, the continuous branching behavior introduced by hybrid systems remains visible even after abstraction from continuous variables. The practical applicability of the introduction of guard trajectories is illustrated by our revision of the structured operational semantics of the CIF language. The interplay between urgency and abstraction now adheres to our intuition, while compositionality with respect to urgency, variable abstraction, and parallel composition, is retained. In the future, symbolic elimination of urgency can be used to ensure that guard trajectories do not need to be actually calculated.

In this paper we propose a simulation modeling approach based on aggregate process times for the performance analysis of order picking workstations in automated warehouses with first-in-first-out processing of orders. The aggregate process time distribution is calculated from tote arrival and departure times. We refer to the aggregate process time as the effective process time. We distinguish between the effective process time distribution for the first tote of an order and that of the remaining totes of an order. These two distributions are used in an aggregate model to predict tote and order flow times. Results from a test case show that the aggregate model accurately predicts the mean and variability of tote and order flow times. The effect of the order size distribution on the flow time prediction accuracy is also investigated.

Hybrid Chi is a process algebra for the modeling and analysis of hybrid systems. It enables modular specification of hybrid systems by means of a large set of atomic statements and operators for combining these. For the efficient implementation of simulators and the verification of properties of hybrid systems it is convenient to have a model that uses a more restricted part of the syntax of hybrid Chi. To that purpose the linearization of a reasonably expressive, relevant subset of the Chi language is discussed. A linearization algorithm that transforms any specification from this subset into a so-called normal form is presented. The algorithm is applied to a bottle-filling line example to demonstrate tool-based verification of Chi models.

The dynamics of manufacturing systems has been a subject of study for several decades. Over the last years, manufacturing systems have become more and more complex. A good understanding of the dynamics of manufacturing systems has therefore become even more important. The goal of this report is to introduce a large variety of models that have been used for modeling manufacturing systems. By means of examples it is illustrated how certain modeling techniques can be used to derive models that can be used for analysis and/or control. Also, references are provided that can be used as a starting point for getting more details. Furthermore, recent developments in the modeling, analysis and control of manufacturing systems are presented.