Introduction

Open source Complex Logistics Simulation

OpenCLSim is a python package for rule driven scheduling of cyclic activities aimed at in-depth comparison of alternative operating strategies.

Book overview

For the design and optimization of waterborne supply chains with a cyclic character, simulation can be a helpful tool. While simulations are not the same as real life data, they still can save time and money as they allow us to explore the unknown. You can investigate the performance of alternative execution strategies and variants of the real world (possible changes to the waterway and/or its infrastructure) before actual implementation.

This book provides an introduction to the use and application of the OpenCLSim package. The goal of this book is to introduce the basics of the package by explaining how to setup your first simulation. After the basics this book will guide you through the set-up of more complex simulations and show a couple of real world examples.

This book intends to serve researchers, engineers and students that want to investigate complex logistics and its interaction with the physical system. OpenCLSim has grown into a community effort to collect algorithms that can represent various cycles: sequential activities, repeating activities, parallel activities. The modules are set up in such a manner that you can create your own cycles depending on your needs. Via various plugins, such as a weather plugin, it is possible to investigate the effect of changing physical conditions on cycle progress. Various processes can be defined as such, including mutual dependencies. A critical path module allows to investigate what activities are critical for the overall planning. Due to its open-source nature, OpenCLSim facilitates an environment where connections with external data, models and tools can be made, such as in-house modules or databases.

Goals

The learning goals of this book are: 1. Learn the basics of OpenCLSim 2. Learn how to create more complex simulations with OpenCLSim 3. Learn how to apply OpenCLSim to real-world examples 4. Learn how to inspect output through logs and the registry

Context / OpenTNSim

OpenCLSim is an open-source Python package which has a sister package OpenTNSim. The development of the tool was started by the Ports and Waterways department for the analysis of maritime transport. Van Oord, Deltares, Witteveen+Bos and Ports and Waterways joined efforts to increase the adaptability and workability of the tool.

OpenCLSim builds on SimPy by the addition of maritime-specific activities: e.g. loading and unloading of items and the moving and storing of items. Furthermore, the addition of components such as, ports, terminals, storage, quays, cranes and vessels, allow for a real-world maritime system to be simulated. To increase the usability of these maritime components and activities, OpenCLSim utilises so-called mixin classes. These mixins represent a certain set of parameters that apply to a type of activity or component. This makes it easier to configure complex supply chains. An example of such a mixin is the mixin Processor. This class has loading and unloading functions and can be used to represent a crane. Other mixin classes, with different properties, can be used to represent other components in the system. Combining different mixins can then be used to represent a port, or ac ontainer vessel.

It is expected that OpenCLSim and OpenTNSim will grow in the future with the growing importance of emissions reduction and with the development of maritime transport.