| 1. |
- Helleboogh, Alexander, et al.
(författare)
-
On adls and tool support for documenting view-based architectural descriptions
- 2008
-
Konferensbidrag (refereegranskat)abstract
- DistriNet is a research lab with +60 researchers. The general domain of expertise and innovation of DistriNet is the development of advanced open and distributed software applications. The research is application driven and is conducted in close collaboration with industry. One particular class of applications we target are decentralized systems that are characterized by a high degree of dynamism and change in either the problem or the system's environment. Example domains of interest are manufacturing control, supply chains, inland shipping, and traffic control.To document software architecture, we follow the approach of views and beyond (V&B). V&B is an approach for documenting software architecture by means of a set of relevant views and adding information that applies to more than one view. Views describe (parts of) the system from different perspectives, exposing different quality attributes that are of interest for particular stakeholders.In several projects in which we applied V&B, we experience that managing and maintaining a consistent architectural documentation is a tedious task, including maintaining the mapping between views, maintaining the related view packets within each view packet, updating context diagrams, maintaining consistency w.r.t. combined views, etc.While V&B offers a well-defined approach to organize architectural documentation,there is a lack of support in ADLs and associated tools for documenting softwarearchitectures that comprise several, interrelated views. Existing ADL tools (e.g. AADL,ArchStudio, AcmeStudio) offer several ways to organize architectural documentation, butdo not support views as first-class concepts of architectural documentation. From ourexperience, there is a gap between the state of the art on documenting softwarearchitectures and the state of the practice in ADL tool-support for documentingarchitecture.We advocate that developing ADLs and tool support specifically targeted at view-basedarchitectural descriptions is imperative. This can significantly increase the level ofcomfort for managing view-based architectural descriptions. As a first step, weinvestigate extending an existing ADL, i.e. xADL, with support for documenting anumber of relations among view packets of structural views. We integrated this extensionin ArchStudio, and used this extended tool for documenting the architectures of a trafficcontrol system as well as a digital newspaper publishing system. We experienced that thetool significantly improves consistency management. Another interesting benefit is that the tool enables an architect to generate composed views on the fly, which was founduseful in the interaction with stakeholders, particularly developers.Currently, we are expanding the scope of xADL and ArchStudio with support fordocumenting view packets and their relations across multiple views. From ourexperience, we put forward a number of challenges that are key to translating the existingbody of knowledge on views and relations into proper tool support. These challengesinclude (1) selecting a set of practical views and relations; (2) formally specifying theseviews and relations, and (3) designing a tool that provides an intuitive user interface,while hiding the complexity that lies beneath.
|
|
| 2. |
- Michalik, Bartosz, et al.
(författare)
-
Supporting Online Updates of Software Product Lines : A Controlled Experiment
- 2011
-
Ingår i: International Symposium on Empirical Software Engineering and Measurement. - : IEEE. ; , s. 187-196
-
Konferensbidrag (refereegranskat)abstract
- The evolution of Software Product Lines (SPL) is challenging because stakeholders have to deal with both regular evolution and the co-existence of different products. Our focus of product evolution is on the tasks integrators have to perform to update deployed SPL products with minimal interruption of services. In case of Egemin, our industrial partner, the updates of SPL products is further hampered as a consequence of outdated and imprecise architectural knowledge of deployed products. To facilitate the updates of products, we have developed the architecture-centric approach which comprises two complementary parts: an update viewpoint and a supporting tool. In this paper we present an evaluation of the architecturecentric approach. The approach is compared with the Egemin's current update approach in a controlled experiment. In the experiment 17 professionals were asked to perform 68 updates of logistic systems. The results obtained from the experiment show that the architecture-centric approach significantly improves the correctness of updates and reduces the interruption of services during updates of Egemin's SPL products.
|
|
| 3. |
- Weyns, Danny, et al.
(författare)
-
An Architectural Approach to Support Online Updates of Software Product Lines
- 2011
-
Ingår i: 2011 Ninth Working IEEE/IFIP Conference on Software Architecture (WICSA). - : IEEE. ; , s. 204-213
-
Konferensbidrag (refereegranskat)abstract
- Despite the successes of software product lines (SPL), managing the evolution of a SPL remains difficult and error-prone. Our focus of evolution is on the concrete tasks integrators have to perform to update deployed SPL products, in particular products that require run-time updates with minimal interruption. The complexity of updating a deployed SPL product is caused by multiple interdependent concerns, including variability, traceability, versioning, availability, and correctness. Existing approaches typically focus on particular concerns while making abstraction of others, thus offering only partial solutions. An integrated approach that takes into account the different stakeholder concerns is lacking. In this paper, we present an architectural approach for updating SPL products that supports multiple concerns. The approach comprises of two complementary parts: (1) an update viewpoint that defines the conventions for constructing and using architecture views to deal with multiple update concerns; and (2) a supporting framework that provides an extensible infrastructure supporting integrators of a SPL. We evaluated the approach for an industrial SPL for logistic systems providing empirical evidence for its benefits and recommendations.
|
|
| 4. |
- Weyns, Danny, et al.
(författare)
-
DynCNET : a protocol for flexible task assignment applied in an AGV transportation system
- 2006
-
Ingår i: Proceedings of the 4th European Workshop on Multi-Agent Systems. ; , s. 359-370
-
Konferensbidrag (refereegranskat)abstract
- The work presented in this paper is part of an ongoing effort to study suitable task assignment mechanismsfor decentralized MAS. Our focus is on systems that are characterized by tasks with delayedcommencement. Such a task requires a preceding effort before the agent can start executing the task. Anexample is a robot that first has to move to the location of a task before it can start executing that task.Important quality requirements for assigning tasks with delayed commencement are flexibility (enableagents to adapt task assignment with changing circumstances) and openness (enable agents to take intoaccount other agents that come and go during the process of task assignment).In previous work, we have studied Contract Net (CNET) and a field-based approach for task assignment(FiTA). CNET does not provide the required flexibility and openness. FiTA satisfies the requiredqualities, however, the field-based approach provides an emergent solution for task assignment. It is wellknown that emergent solutions are difficult to engineer and reason about. This raises the question whetherit is not easier to extend CNET to take dynamics and changes into account.This paper presents the DynCNET protocol. DynCNET is an extention of CNET, with “Dyn” referringto support for dynamic task assignment. DynCNET provides flexibility and openness for assigningtasks with delayed commencement. We compare the DynCNET protocol with CNET and FiTA in anAGV transportation system. Our experiences in this real-world setting show that: (1) the performance ofDynCNET and FiTA are similar, while both outperform CNET; (2) extending CNET to deal with delayedcommencement of tasks is not obvious; the complexity to engineer DynCNET is similar to FiTA but muchmore complex than CNET; (3) whereas task assignment with FiTA is an emergent solution, DynCNETexplicitly specifies the interaction among agents allowing engineers to reason on the assignment of tasks.This latter property may be of overriding importance in the selection of an agent-based approach for task assignment in practice.
|
|
| 5. |
|
|
| 6. |
- Weyns, Danny, et al.
(författare)
-
Gradient field-based task assignment in an AGV transportation system
- 2006
-
Ingår i: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems. - New York, NY, USA : ACM. - 1595933034 ; , s. 842-849
-
Konferensbidrag (refereegranskat)abstract
- Assigning tasks to agents is complex, especially in highly dynamic environments. Typical protocol-based approaches for task assignment such as Contract Net have proven their value, however, they may not be flexible enough to cope with continuously changing circumstances. In this paper we study and validate the feasibility of a field-based approach for task assignment in a complex problem domain.In particular, we apply the field-based approach for task assignment in an AGV transportation system. In this approach, transports emit fields into the environment that attract idle AGVs. To avoid multiple AGVs driving towards the same transport, AGVs emit repulsive fields. AGVs combine received fields and follow the gradient of the combined fields, that guide them towards pick locations of transports. The AGVs continuously reconsider the situation of the environment and task assignment is delayed until the load is picked, improves the flexibility of the system.Extensive experiments indicate that the field-based approach outperforms the standard Contract Net approach on various performance measures, such as the average wait time of transports and throughput. Limitations of the field-based approach are an unequal distribution of wait times across different transports and a small increase of bandwidth occupation.
|
|
| 7. |
- Weyns, Danny, et al.
(författare)
-
On-demand Generation of Views to Support Online Evolution of Software Product Lines
- 2011
-
Ingår i: Proceedings of the 7th SEI Architecture Technology User Network Conference. - : Software Engineering Institute.
-
Konferensbidrag (refereegranskat)abstract
- It is difficult to achieve assured conformance between architecture and code. We lacked proper architecture descriptions in the context of the evolution of an industrial software product line of logistic systems. As a result, a lack of explicit architecture documentation about the deployed products led to ad hoc update practices, which were error prone and resulted in unnecessary and undesirable shutdowns. To tackle these problems, we have codified the architecture knowledge required for evolving products in a viewpoint. Based on this viewpoint, we developed a supporting tool that allows generating on-demand architecture models. These models guide maintainers by listing the concrete tasks they need to perform when upgrading a system and by showing inconsistencies when they fail to do so. The evaluation of 68 updates of industrial logistic systems demonstrates a significant improvement in the quality of system updates with respect to the correct execution of updates and a reduced interruption of services.
|
|
