Juliane Fischer

Modularity and Architecture of PLC-based Software for Automated Production Systems: An analysis in industrial companies

Adaptive and flexible production systems require modular and reusable software especially considering their long-term life cycle of up to 50 years. SWMAT4aPS, an approach to measure Software Maturity for automated Production Systems is introduced. The approach identifies weaknesses and strengths of various companies’ solutions for modularity of software in the design of automated Production Systems (aPS). At first, a self-assessed questionnaire is used to evaluate a large number of companies concerning their software maturity. Secondly, we analyze PLC code, architectural levels, workflows and abilities to configure code automatically out of engineering information in four selected companies. In this paper, the questionnaire results from 16 German world-leading companies in machine and plant manufacturing and four case studies validating the results from the detailed analyses are introduced to prove the applicability of the approach and give a survey of the state of the art in industry.

Challenges for maintenance of PLC-software and its related hardware for automated production systems: Selected industrial Case Studies

The specific challenges for maintenance of software and its related hardware for the domain of automated Production Systems is discussed. Presenting four industrial case studies from renowned and world market leading German machine and plant manufacturing companies, these challenges and different solution approaches are introduced with a focus on software architectures to support modularity as a basis for maintaining long-living automated Production Systems. Additionally, most critical aspects hindering classical approaches from software engineering to be successful, e.g., modes of operation and fault handling, are discussed. In the last decades, research in the field of software engineering for automated Production Systems (aPS) has been focusing on developing domain specific model-driven engineering approaches supporting the development process, but mostly neglecting the operation, maintenance and re-engineering aspects. However, the success of model-driven engineering in aPS industry has been limited because the effort to introduce model-driven engineering and to change the entire existing legacy software is estimated as too high and the benefit as too low against the background of customer specific solutions expecting a low degree of reuse.

Configuration of PLC software for automated warehouses based on reusable components- an industrial case study

In the development of PLC software for automated Production Systems the method copy & paste is commonly used. However, this method leads to various disadvantages. To avoid these disadvantages, a parameter-based concept for planed reuse is presented in this paper. By means of the Siemens PLC software of an automated warehouse, the concept is defined and evaluated. In a first step, the PLC software is analyzed and reusable parts as well as variation points are identified. Subsequently, it is demonstrated that the warehouse variants can be clearly described by a suitable set of parameters. In a last step the automatic configuration of the PLC software by using the identified parameters as well as a Step7 source code template is explained and evaluated.

Model-based development of a multi-agent system for controlling material flow systems

Abstract The rising number of product variants requires flexible manufacturing systems, including their internal material flow systems (MFSs). An approach to design MFSs reconfigurably is the use of a decentralized control based on software agents. For implementing an agent-based control approach for MFSs this paper presents a meta model describing the knowledge base of individual agents and the overall control task to be fulfilled by the MFS.

Variability management for automated production systems using product lines and feature models

Increasing numbers of variants and versions in the domain of automated Production Systems (aPS) demand appropriate methods to handle this variability. While software product lines (SPLs), often in combination with feature modelling, are already well established in the domain of information systems, up to now SPLs are rarely used in the domain of aPS. Also, SPLs for aPS need to include variants and versions in mechanic and electric besides software leading to interdisciplinary product lines (IPLs). In this paper an existing approach of an IPL is enhanced with extended feature modelling methods and SPLs and, subsequently, applied to two industrial case studies — one in special purpose machinery and the other in plant manufacturing. Challenges for such automated Production Systems are discussed.