CarLogistics

Description

We present a logistic scenario, based on the sea port of Bremen, and a context-aware dynamic service-based system to support its operation. The scenario is based on the operation of the sea port of Bremen, Germany, where nearly 2 million new vehicles are handled each year; the business goal is to deliver them from a manufacturer to a dealer. Each car, depending on its brand, model and specific order, needs to follow certain customizable procedures during the delivery process. Cars arrive by ship and are unloaded and unpacked at a certain terminal. Each ship is able to approach and leave a gate interacting with the landing manager, which is in charge of coordinating and controlling the landing procedure for all the ships in the port. Once a car is unpacked to a terminal, a communication is established with the storage manager to book a place at storage facilities. The storage place is located in one of the available storage areas, each having its own parking procedure and suitable for a specific car type (e.g., covered/guarded areas for luxury cars). Once a stored car is ordered by a retailer, it continues its way towards the delivery. In particular, cars are treated at dedicated treatment areas (such as washing, painting, equipment, repairing) according to the details in the order. When a car is ready to be delivered, it is assigned to an available delivery gate and truck. The latter is responsible for loading a limited number or cars and deliver them to the dealer.

The goal is to develop an application (the Car Logistics System, CLS) to support the management and operation of the port as described above, where numerous actors (i.e., cars, ships, trucks, treatment areas, etc.) need to co-operate in a synergic manner respecting their own procedures and business policies. The system needs to deal with the dynamicity of the scenario, both in terms of the variability of the actors’ procedures (customizable processes), and of the exogenous context changes affecting its operation. Customization means that different brands and models of cars should be treated in a similar but customizable way. Moreover new car models, having specific requirements and procedures, must be easily integrated in the application. Similarly, the application needs to flexibly deal with changes in the procedures of external entities such as ships and trucks. Finally, the application needs to promptly implement changes in international regulations and laws.

Basic technology

Adaptive and context-aware service-based systems are modeled by defining a set of entities. Each of them features its own business process and its provided services. Business processes are modeled as Adaptable Pervasive Flows (APFs) [1], an extension of traditional workflow language (e.g., BPEL) which makes them more suitable for adaptation and execution in dynamic environments. In addition to the classical workflow language constructs, APFs add the possibility to model abstract activities. An abstract activity is defined at design time in terms of the goal it needs to achieve and is dynamically refined at run-time into an executable process, considering the set of available services, the current execution context and its goal.

Each entity can provide a set of services to the other entities. We consider services to be stateful: they can expose complex protocols (e.g., BPEL) combining traditional service actions (i. e., sending/receiving messages to/from services) with control flow structures (e.g. switch, while, pick).

The application context is modeled as a set of context properties, each describing a particular aspect of an application domain. Every context property is modelled with a context property diagram, which is a state transition system capturing all possible property values and value changes. Each transition is labeled with a corresponding context event. A context property may evolve as an effect of service invocations, which corresponds to the normal behavior of the domain, but also as a result of volatile exogenous changes.

How to install

If applicable, please give a clear procedure for installing the artifact

How to use

We have created a visualization environment enabling interaction between the framework and the user and simulating execution and adaptation of business processes in our case study. In particular, it can:

(i) run the CLS and simulate the execution and adaptation of each business process attached to each entity and (ii) view the different adaptation strategies supported by our framework and how they are used during the scenario execution.

The goal of this demonstrator is to show the novel concepts and advantages of the CAptEvo Framework when applied to a real and complex pervasive system.

Download

All the artifacts of the Car Logistics Scenario (CLS) can be downloaded from: http://www.astroproject.org/downloads/artifacts.zip. The specification of the CLS we used to evaluate our approach is composed by 29 entities, 69 services and 40 context properties. Moreover to see the ASTRO-CAptEvo framework in action, one can download the complete demo and a video of a live demonstration from: http://www.astroproject.org/captevo.

Additional info

Link to papers or technical reports that could be useful to understand and use the artifact