Jörg Lenhard

Jörg Lenhard

Dr. rer. nat.

About

40
Publications
21,764
Reads
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384
Citations
Citations since 2017
15 Research Items
275 Citations
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20172018201920202021202220230204060
20172018201920202021202220230204060
20172018201920202021202220230204060
Additional affiliations
May 2016 - present
Karlstads Universitet
Position
  • PostDoc Position
April 2011 - April 2016
Otto-Friedrich-Universität Bamberg
Position
  • Research Assistant

Publications

Publications (40)
Book
Improve your coding skills by comparing your code to that of expert programmers, so you can write code that’s clean, concise, and to the point: code that others will read with pleasure and reuse. Get hands-on advice to level up your coding style through small and understandable examples that compare flawed code to an improved solution. Discover han...
Article
Full-text available
Software architecture degradation is a phenomenon that frequently occurs during software evolution. Source code anomalies are one of the several aspects that potentially contribute to software architecture degradation. Many techniques for automating the detection of such anomalies are based on source code metrics. It is, however, unclear how accura...
Conference Paper
Full-text available
Learning programming is hard – teaching it well is even more challenging. At university, the focus is often on functional correctness and neglects the topic of clean and maintainable code, despite the dire need for developers with this skill set within the software industry. We present a feedbackdriven teaching concept for college students in their...
Chapter
Workflow engines are frequently used in the service-oriented and cloud computing domains. Since engines have significant impact on the quality of service provided by hosted applications, it is desirable to compare and select the most appropriate engine for a given task. To enable such a comparison, approaches for benchmarking workflow engines have...
Conference Paper
Full-text available
Workflow Management Systems (WfMSs) today act as service composition engines and service-oriented middleware to enable the execution of automated business processes. Automation based on WfMSs promises to enable the model-driven construction of flexible and easily maintainable services with high-performance characteristics. In the past decade, signi...
Conference Paper
Full-text available
Context: Several studies suggest that there is a relation between code smells and architecture degradation. They claim that classes, which have degraded architecture-wise, can be detected on the basis of code smells, at least if these are manually identi€fied in the source code. Objective: To evaluate the suitability of contemporary code smell dete...
Conference Paper
Context: Facing the implementation of the EU General Data Protection Regulation in May 2018, many commercial software providers will soon need to adapt their products to new privacy-related constraints. Privacy patterns defined for different aspects of the software engineering process promise to be a useful concept for this task. In this situation,...
Conference Paper
Full-text available
Workflow engines are frequently used in the domains of business process management, service orchestration, and cloud computing, where they serve as middleware platforms for integrated business applications. Engines have a significant impact on the quality of service provided by hosted applications. Therefore, it is desirable to compare them and to...
Chapter
Full-text available
Workflow Management Systems (WfMSs) today act as service composition engines and service-oriented middleware to enable the execution of automated business processes. Automation based on WfMSs promises to enable the model-driven construction of flexible and easily maintainable services with high-performance characteristics. In the past decade, signi...
Chapter
Runtimes for process-aware applications, i.e., process engines, constantly evolve and in the age of cloud-enabled process execution, the need to change a runtime quickly becomes even more evident. To cope with this fast pace, it is desirable to build processes in a way that makes them easily portable among engines. Reliance on process standards is...
Article
The Business Process Model and Notation 2.0 (BPMN) standard has been hailed as a major step in business process modeling and automation. Recently, it has also been accepted as an ISO standard. The expectation is that vendors of business process management systems (BPMS) will switch to the new standard and natively support its execution in process e...
Article
Full-text available
A key promise of process languages based on open standards, such as the Web Services Business Process Execution Language, is the avoidance of vendor lock-in through the portability of processes among runtime environments. Despite the fact that today various runtimes claim to support this language, every runtime implements a different subset, thus h...
Article
Full-text available
Business process management and automation has been the focus of intense research for a long time. Today, a plethora of process languages for specifying and implementing process models have evolved. Examples for such languages are established international standards, such as BPEL 2.0 or, more recently, BPMN 2.0. Implementations of these standards w...
Conference Paper
Business process management and automation has been the focus of intense research for a long time. Today, a plethora of process languages for specifying and implementing process models have evolved. Examples for such languages are established international standards, such as the Web Services Business Process Execution Language 2.0 or, more recently...
Thesis
Full-text available
Modern software systems are becoming increasingly integrated and are required to operate over organizational boundaries through networks. The development of such distributed software systems has been shaped by the orthogonal trends of service-orientation and process-awareness. These trends put an emphasis on technological neutrality, loose coupling...
Article
Full-text available
Over the last years, the utilization of cloud resources has been steadily rising and an increasing number of enterprises are moving applications to the cloud. A leading trend is the adoption of Platform as a Service to support rapid application deployment. By providing a managed environment, cloud platforms take away a lot of complex configuration...
Conference Paper
Full-text available
Over the last years, the utilization of cloud resources has been steadily rising and an increasing number of enterprises are moving applications to the cloud. A leading trend is the adoption of Platform as a Service to support rapid application deployment. By providing a managed environment, cloud platforms take away a lot of complex configuration...
Conference Paper
Service-oriented systems are increasingly implemented in a process-based fashion. Multiple languages for building process-based systems are available today, but the Business Process Model and Notation (BPMN) is becoming ubiquitous. With BPMN 2.0 released in 2011, execution semantics were introduced, supporting the definition of executable processes...
Conference Paper
Today, process languages are frequently used for implementing service-oriented systems and a variety of specifications for this task exist. These specifications strive for the portability of processes among different runtime environments, i.e., process engines. However, direct portability, especially of executable processes, is seldom achieved. If...
Conference Paper
Process languages such as the Business Process Model and Notation 2.0 or the Web Services Business Process Execution Language promise the portability of executable artifacts among different runtime environments, given these artifacts conform to the respective specification. However, due to the natural imperfectness and differing priorities of runti...
Article
The Web Services Business Process Execution language (BPEL) is a standard for modeling and executing automated processes and is tailor-made for service orchestration. BPEL specifies a serialization format which every BPEL implementation has to understand, thus allowing for the portability of processes among runtime engines. Although the modeling an...
Conference Paper
Service-oriented software consists of middleware, such as application servers and runtime engines, into which service applications are deployed. This middleware is often complex and difficult to install. The deployment of services requires the crafting of deployment descriptors and packaging of applications. As a consequence, the installation of se...
Conference Paper
It is a long-standing debate, whether software that is developed as open source is generally of higher quality than proprietary software. Although the open source community has grown immensely during the last decade, there is still no clear answer. Service-oriented software and middleware tends to rely on highly complex and interrelated standards a...
Conference Paper
A key promise of process languages based on open standards, such as the Web Services Business Process Execution Language, is the avoidance of vendor lock-in through the portability of process definitions among runtime environments. Despite the fact that today, various runtimes claim to support this language, every runtime implements a different sub...
Conference Paper
Service orchestration languages, like the Web Services Business Process Execution Language (BPEL), have been frequently used to provide an implementation platform for model-driven development approaches. As avoidance of vendor lock-in and portability of process definitions are central aims of BPEL, most approaches claim to support a large set of di...
Conference Paper
More than five years have passed since the final release of the long-desired OASIS standard of a process language for Web Services orchestration, the Web Services Business Process Execution Language (BPEL). The aim of this standard was to establish a universally accepted Web Services orchestration language that forms a core part of service-oriented...
Conference Paper
Full-text available
Service orchestrations are a powerful tool for implementing intra- and interorganizational business processes that base on services. Several heterogeneous orchestration languages can be found in contemporary IT landscapes. While the Web Services Business Process Execution Language (BPEL) is the de facto standard, others gain attention, including Wi...
Conference Paper
Full-text available
Various approaches for service-oriented business-to-business integration (B2Bi) rely on a top-down development methodology. The starting point is a choreography model which is subsequently partitioned into multiple orchestrations. Most current approaches use the Web Services Business Process Execution Language (BPEL) for implementing the latter. At...
Conference Paper
Full-text available
Orchestration languages are of paramount importance when implementing business processes based on services. Several languages for specifying Web Services-based orchestrations are available today. Examples are the Web Services Business Process Execution Language or Windows Workflow. Patterns for process-aware information systems have frequently been...
Conference Paper
Full-text available
Various process modeling formalisms have been leveraged to specify service compositions. For assessing the expressiveness of similar languages and for providing best practice knowledge, patterns have frequently been proposed. However, the pattern catalogs proposed do not all share and document the criteria that were used for assessing pattern suppo...
Conference Paper
Full-text available
Being able to access and provide Internet services anony- mously is an important mechanism to ensure freedom of speech in vast parts of the world. Offering location-hidden services on the Internet re- quires complex redirection protocols to obscure the locations and iden- tities of communication partners. The anonymity system Tor supports such a pr...

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Projects

Projects (4)
Project
n both industry and academia, multiple process languages have emerged, e.g. Windows Workflow (WF), Business Process Model and Notation (BPMN) and Web Services Business Process Execution Language (WS-BPEL). These standards have been implemented in process runtime environments (process engines) by variant sofware vendors and open source communities. All of these process engines have two thing in common: they implement a standard-based process language and are inherently complex in regard to their inner structure, installation procedures and usage in general. This complexity in both standard and implementation aggravates a deliberate selection of such a process engine for a project in industry or academia. For example, there are eight different implementations for WS-BPEL currently available. Within this research project, a comparative framework for process engines in general is developed. This framework is applied to and validated with BPEL as well as BPMN engines. It focuses on the comparison of standard conformance, performance, error detection as well as automation.