Quality custom essays
A more recendy developed style-based approach, building on our work as well as that of Tamzalit, Le Goaer, et al. Thus, unlike our approach, they do not provide any way of evaluating evolution paths holistically to identify the optimal path, nor any way of making utility-based trade-offs among competing concerns. This work is focused specifically on co-evolution of related artifacts and is not a general theory of software architecture evolution. Making trade-offs among architecture evolution paths. Another area of quality custom essays work is trade-off analysis for architectural evolution.
Also like us, they use cost-benefit analyses to evaluate and select among these evolution paths.
They present a methodology for capturing evolution decisions in a decision map (similar to a conventional mind map). This work focuses solely on capturing and relating decisions and does not directly represent architectural structure.
In addition, while our work focuses on providing guidance to help architects make good decisions, Zalewski et al. There has also been work on evolution in the model- driven engineering community. Model-based reengineering has seen some industrial use.
Most of these are fairly limited, but they do show how model-based approaches to software evolution can be made industrially relevant.
They present the case of a loan-servicing company that was migrating from a mainframe system to an event-driven, service- oriented architecture. The advice is pragmatic in nature, suggesting that introducing major infrastructure changes (waves) should be followed by periods of relative stability to permit adjustment to new infrastructure changes (plateaus). They observed that the evolution they studied adhered to a pattern of punctuated equilibrium, characterized by large 151 7 Related work expansions of functionality that were often followed by periods of retrenchment in which the number of services receded slightly. Based on the results of these case studies, Bratthall argues that improving architectural understanding of a system can reduce development time. Like the work described in this dissertation, these approaches can take advantage of domain-specific classes of systems and thereby achieve analytic leverage, as well as tool support for evolution. However, these approaches are limited to a particular architectural style. But again, such sources are aimed at characterizing a single evolution domain and do not relate the example to a general approach to architecture evolution. It does, however, have much in common with the work described in section 7. In that section, I mentioned some of the ways in which our approach distinguishes itself from particular other approaches. But it is useful here to summarize the main characteristics that make this thesis research unique. Our approach is concerned with defining, analyzing, evaluating, and selecting among multiple candidate paths of evolution leading from the current state of a system to a desired target state. A key idea in our approach is the use of evolution styles to encapsulate a set of operators and analyses relevant to a domain of evolution.
Other approaches tend to be either fully generic (lacking any support for domain specialization) or fully domain-specific (applicable only to a single domain and otherwise useless). Other work in this area has tended to rely heavily on artificial examples—evolutions imagined in general terms but never actually carried out. In addition to this empirical evaluation, we have also undertaken a detailed theoretical study of specification and verification issues (chapter 3) as well as some prototype tool development work to examine issues of im- plementability (chapter 6). Together, these different evaluation approaches provide a validation that is quite robust in comparison with existing work in this area.
These results are of interest in this work on software architecture evolution because they characterize the difficulty of evolution path constraint verification.
The Costco case study provides particularly robust results in this respect, due to its careful methodological design and rigorous execution, and also because it evaluated all the elements of our approach (in contrast to the JPL case study, which focused on the construction of an evolution model and did not examine the issue of model analysis in depth). The argument is particularly strong because Costco and JPL are extremely different organizations—a retailer and a government-funded laboratory. If our approach can be applied in these very disparate contexts, we can reasonable conclude that it likely has a fairly broad scope of applicability. These results help us to position our research, but they may also be of broader use beyond this work. There has been very little work directed at systematically examining the impetuses of architecture evolution, the architecture evolution challenges perceived by real-world architects, and the approaches by which architects manage evolution today. This case study provides some useful results on these questions, beyond its immediate relevance to our research. In addition to its overt contributions to software architecture evolution research, the Costco case study also makes a significant methodological contribution. The use of content analysis to mine architectural elements from architectural documentation is a novel approach that I hope will be of use best online essay writer to other software architecture researchers. Usually, software architecture case quality custom essays studies are fairly informal. In particular, researchers constructing architectural models of systems tend to rely heavily paraphrasing paragraph on their own understanding and intuition about the system being modeled. The use of content analyses systematizes the process of model construction, reducing the risk that researcher bias will taint the results, and significantly improving replicability. It is my hope that this novel methodological approach to empirical software architecture research, or variants of it, might be adopted by other software architecture researchers working with heterogeneous real-world data. These prototype tools have demonstrated how the approach presented quality custom essays in this dissertation can be implemented in practical tools that leverage existing architecture modeling frameworks. In addition to these general results on implementability, they have allowed us to explore how various aspects of our approach can be automated, such as the application of evolution operators and the generation of evolution paths. At the same time, this tool work has revealed areas where significant research challenges still remain, such as relating multiple architectural views of an evolution state and using constraints and evaluation functions to automatically generate evolution paths.
In this section, quality custom essays I highlight a number of noteworthy limitations.
The approach carries a significant specification burden. The approach presented in this thesis requires essay introduction help significant formal specification, including specification of evolution elements such as operators, constraints, and evaluation functions as well as specification of an evolution space in terms of intermediate architectural states and evolutionary transitions among them.
The significant specification effort required may make our approach seem a bit heavyweight, limiting its adoptability. There are a couple of ways in which this burden is mitigated. An evolution style allows a set of operators, constraints, and evaluation functions relevant to an evolution domain to be bundled together in such a way that they can be applied repeatedly to evolution projects within that domain. In this way, the cost of specifying the evolution elements is amortized over a large number of systems.