LLAMA: A Layered Logical Architecture for Material Administration

Material handling systems are an information bridge between high-level shop floor control and the sensors and actuators at the factory floor. When such systems are engineered as a monolith, each must be custom-built, and the cost of modification and maintenance is high. Drawing on parallels between communications (moving data) and material handling (moving material), we propose a layered architecture analogous to the ISO OSI reference model for communications. This article defines the problem, discusses layered architectures in general and previous layered systems in particular, and describes the functions and interfaces of the layers in our system. This is a working paper describing work in progress, not a finished specification.