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The amount of software in automated production systems, including its development effort, is continuously increasing to currently up to 35-50% of the development personnel. Consequently, success factors for achieving modularity and complexity management of control software are of high economic interest. Scientific solutions are manifold but often n...
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... high percentage of high-level programming languages (cp. Figure 2) cannot be explained by the programming of HMI or Manufacturing Execution Systems (MES) because the question (#17) was clearly specified, asking only for control code excluding HMI. However, we need to assume that either validity is poor, because consistency checks with control platforms failed (74% of companies using high-level languages on control level do not match with the control platforms, as some of them do not support high-level languages) or PLC code is automatically generated from high level programming languages. ...
Citations
... For this paper, the focus is on the documentation aspect of the questionnaire, which was not the target of the previous investigation [7]. Hereafter, #[number] denotes a question with the ordinate number in the questionnaire available online [24]. The eight questions used in this analysis are listed in the Appendix. ...
... Table 4). The internal Table 4: Evaluation of expert surveys on usage of PLCopen and company-specific guidelines in software discipline (#34 [24]). ...
... Evaluation of expert surveys on document accessibility across disciplines (#72[24]). ...
This paper first examines the current state of industrial practice of documentation in automated production systems based on a large-scale survey in machine and plant manufacturing proving that companies still face major challenges in documentation. However, insufficient documentation creates friction since it may increase the risk of malfunction and high costs, and impede system development due to lack of traceability, especially for control software being one of the main functionality carriers. Therefore, secondly, a risk priority indicator RPI4DD is proposed to systematically capture the lack of control code documentation to avoid undesired costs due to inadequate documentation.
... In computer science object-oriented (OO) programming is successfully applied to enable encapsulation, standardized interfaces and reuse. Although the last update of the PLC programming standard IEC 61131-3 enables OO for PLCs, it is not yet established in industry and guidelines for its application are rare [7]. To bridge this gap and illustrate the challenges and potential solutions to deal with extra-functional software parts, this paper gives an introduction to the design decisions required to implement error handling. ...
... Although many platform providers meanwhile support the OO IEC concepts, a conservative, procedural programming approach is still predominant in most companies, which was confirmed by a recent survey: only 10% of the participating companies use OO IEC by default, 48% apply it partially and 42% do not use it at all [18]. Another recent questionnaire study confirmed this low usage rate of OO IEC with around 40% for machine and plant manufacturers [6], [7]. Out of 61 participants, only 24 companies indicate to use interfaces/properties and OO IEC. ...
Cyber-Physical Production Systems (CPPS) are long-living and mechatronic systems, which include mechanics, electrics/electronics and software. The interdisciplinary nature combined with challenges and trends in the context of Industry 4.0 such as a high degree of customization, small lot sizes and evolution cause a high amount of variability. Mastering the variability of functional control software, e.g., different control variants of an actuator type, is itself a challenge in developing and reusing CPPS software. This task becomes even more complex when considering extra-functional software such as operating modes, diagnosis and error handling. These software parts have high interdependencies with functional software, often involving the human-machine interface (HMI) to enable the intervention of operators. This paper illustrates the challenges in documenting the dependencies of these software parts including their variability using family models. A procedural and an object-oriented concept for implementing error handling, which represents an extra-functional task with high dependencies to functional software and the HMI, are proposed. The suitability of both concepts to increase the software's reusability and, thus, its flexibility in the context of Industry 4.0 is discussed. Their comparison confirms the high potential of the object-oriented extension of IEC 61131-3 to handle planned reuse of extra-functional CPPS software successfully.
Machine and plant automation in the timber (wood) industry and paper industry has many analogies due to the similar process characteristics, i.e., hybrid process and coupled drives. From a plan automation point of view, these industries are challenging because of their technical requirements. Requirements in fiber industry are even more challenging regarding coupled drives and robustness against unstable power supply, but are continuous processes.Woodworking, paper, and fiber machinery belong to machine and plant manufacturing industries with their typical business characteristics. Automation in this field is technology driven, and its importance is growing because more functionalities are being implemented using automation software to increase systems flexibility, but costs are essential. The interface from automation level to enterprise resource planning (ERP) systems is being standardized in international manufacturing companies. Often, in-between manufacturing execution systems (MES) that provide an overview on key performance indicators and overall equipment effectiveness (OEE). Efficiency and automation of engineering are the key success factors for this cost-sensitive market. Therefore, modularity and reusability are essential. For a German supplier, more advanced functionality and higher OEE needs to be met despite more sophisticated products and various products. All three sectors require to offer Industry 4.0 as well as smart data concepts.KeywordsSoftware engineeringUnified modeling languageProgrammable logic controllerCyber-physical production systems
