Literature Review: The Use of Patterns in Architecture - Essay Example

Literature Review: The Use of Patterns in Architecture The use of patterns in architecture represents the view of using archetypal and reusable descriptions as representations of architectural design ideas. These patterns are used as guidelines in designing of buildings and cities. A collection of the various patterns is viewed as a pattern language of whose elements or components may be regulated through various rules. Architecture patterns seek to bring forth usable ideas through which people and communities can follow in the construction of their buildings. This also enable the idea of the beauty and comfort brought out by constructing buildings. Those dwelling in this areas can become aware of their ideal construction buildings and hence able to challenge any conflicting ideas. In their development, patterns record the various designs as presented by different artists in solving specific challenges. With time, these patterns keep evolving based on the different situations and challenges that they relate to. In this way, always being modified to fit better into the various implementation scopes. In an article by M.A Ali Babar. T. Dingsoyr. P. Lago. H. Van Vliet. Software Architecture Knowledge Management . Springer Velrage 2009. The challenge of applying appropriate architectural patterns in real life from the many choices are addressed. This is largely attributed to the fact that in the society, they lack uniformity and consensus in relation to granularity and coherence in the pattern languages. As a result,this article establishes a proposal of a single pattern language that will be above the other proposed pattern languages; one that will be uniformly accepted and understood in its various application arenas. It proposes the establishment of this language pattern that focuses on the various relationship natures of the many patterns. It also bases its categorization technique on the different architectural views. The article establishes finding common ground between architectural patterns and style and establishing the pattern language. Through the consideration that both architectural styles and architectural patterns are the same type of problem solving solutions (M.A 45). The only difference is in the fact that they are using description forms that are different from each other. A pattern is considered to be architectural provided that it covers not just the individual subsystems but the overall system structure. The authors proposed that the classification of architectural patterns can be done through consideration of architectural views. The establishment of this single pattern language ensures that architectures can benefit from the use one comprehensive source pattern. This is due to the fact that the patterns are related to each other hence establishing a comprehensive language solution pattern. The article is based on categorizations that deal with connectors and components. The patterns that form fundamental initial catalogues are regarded as a gateway to even greater pattern language development that will encompass all views and patterns and can be used uniformly in practice (M.A 69). In an article by De Boer , R, C and Jansen A, Architectural knowledge: Getting the core : Quality of Software Architectures. pp.197-214 2008. The use of patterns in architecture is linked to the reduction of risk. The article discusses the various ways through which architectural patterns are beneficial in the better management and reduction of both delivery and architectural risks. It states that the relevance of patterns to architecture is based on their ability to be repeated and reused. Patterns are associated with the architect’s abilities enable them to provide solutions to challenges not just based on realistic natures of the problem but, on the more abstract aspect of the pattern or experience (De Boer 75). It is also possible in some cases to define patterns to such extents that they constitute of designed templates that are specifically detailed. These can further be leveraged to establish an implementation approach of a cookie cutter. The initial implementation of a pattern reduces the potential future risks in implementation. Version upgrades and changes can also be conducted at a single pattern level and then transmitted across the whole pattern language system. This prevents against the occurrence of fallouts in implementation. Patterns also support architectural agility to change. This means that through the use of patterns in architecture is much simpler and less costly since it has established the various fundamental changes without altering the totality of practice of architectural designs and technique. Patterns are also used in the definition and management of scopes of practice. This is tied to the challenge of working through the use of agile projects or unclear regulations. A pattern based approach is best in such situations to manage this scope operational risk. This is though the definition of the scope in terms of numbers ad patterns of installation patterns (De Boer 53). Design patterns were first introduced as a fundamental concept by Christopher Alexander in his book The timeless Way of building and A pattern Language New York Wiley and Sons. 2009. Print . Alexander is an architect who envisioned a method to capture all of the best aspects of architectural design in a very simple way to understand in which he termed as “Patterns” . By doing so, it enables architects, engineers and even a layman who would be able to use the buildings to communicate design ideas easily so that they will be able to understand the problem that each design is facing. Ultimately, Alexander wanted his pattern library to be put to the public so that it can help improve the quality of their life in terms of the building designs that they wanted. In his book he hoped to capture what he refers to as the “quality without a name” which he defined as “ there is a central quality which is the root criterion of life and a spirit in a man, town and a building. This quality is objective and precise, however it cannot be named (Alexander 54). In essence, the type of quality designs in this book will be effective when making a space more pleasant, usable or relaxing experience. What makes this emphasis so important is in the focus of the design and where it is placed. The central idea is to determine the needs and desires of the inhabitant ahead of all the other design decision that need to be factored in. The notion of inhabitant –centric architecture design in and of itself is to make pattern usage an important technique. Despite the fact that patterns truly excel, the communication of the common problems that designers face and offering potential solutions is quite difficult. Alexander states that every pattern has essential parts.The context which describe a recurring set of numerous situation in which the patterns can be implemented, the problem which refers to a set of forces which occur in the context and the solution which refers to a design form or rule that will be used to resolve the forces (Alexander 68). By including these components, the pattern is guaranteed to address the core issues that a designer is looking to solve and give a viable method for solving the problem. Another advantage to this is that most of the people will eventually inhabit the area. It is evident that architects understand the concepts so that they can take part in the design process,communicating the needs and desires to the designer. In an article by Frank Buschmann and Kevlin Henney. Explicit interface and object manager.In Proceedings of 8th European Conference on Pattern Languages of Programs (EuroPlop 2003), Irsee, Germany, July. 2003. The authors discuss the architectural pattern that helps to define the types of relationships and elements that work together in order to solve a particular problem from a specific perspective. This article explains why an architectural pattern should be considered as a specialization of a view point since it provides specific semantics to different types of elements and relationships in addition to constraints on them. The essential issue however is hoe the architectural views go hand in hand with the architectural pattern ( Buschmann 48). The authors discuss two major approaches with regard to the use of architectural patterns. Firstly, they consider the views composed of large granularity and how the elements and relationships seem to be generically defined. Thus, a coarse –grained view in multiple architectural patterns can be effective and applied in this scenario. For example, in a structural view. This describes how a system is structurally decomposed into components and connectors. With this regard, we can apply the pipes and filters and layer pattern. Some of the well established examples are Kruchten “4+1” that is also known as the Seimens 4 model and the Zachman framework. Despite the fact that this does not prescribe any specific set of view, it considers the views of such granularity and more specifically the behavioral and structural views. The second approach discussed in this article considers that each architectural pattern is similar to a view in a one to one mapping which is specifically advocated to (CBB+02). This notion is regarded to be on a course for more fine grained as it leads to relationships and elements of very specialized semantics. For instance, when you consider a pipe and filter view. This view is categorized into what is known as view types in which the same granularity as with the first approach. If you follow the middle path of the two approaches discussed in the aforementioned approaches, it is evident that the views should be more of fine grained than that of the of course grained in the first approach will be more useful (Buschmann 68). We consider the types of architectural patters as more of course grained than fine grained. Paul Clements, Felix Bachmann, Len Bass, David Garlan, James Ivers, ReedLittle, Robert Nord, and Judith Stafford. Documenting Software Architectures: Views and Beyond. Addison-Wesley, 2002. The authors claim that client /server architectural style helps to describe the distributed systems that are involved in a separate client and a server system with some kind of connecting networks. The easiest and the most simplest form of client/server system involves a server application that is used and accessed directly by many clients and is referred to as 2-teir architectural style. The client/server architecture has indicated a graphically a graphical desktop UI application that communicates with a database server that contains much of the business logic with a dedicated file server (Paul Clements et al 56). The client/ server architectural style describes the relationship between the client on one or more servers. This is where the clients initiate their request using the graphical UI and awaits responses. The server may send responses using a range of protocols and data formats that will be able to enhance communication with the customer. This article also explains other variations such as Client –Queue –client systems which will allow clients to communicate with other clients through the server based queue. There is also peer to peer applications that allow the client and server to swap their roles so that they can distribute and synchronize files and information across multiple clients (Paul Clements et al 45). The last variation discussed in this article is application servers is a specialized architectural style where the server hosts and executes applications and services that the clients can access through a specialized client installed software. This type of architectural pattern has the main benefits of higher security, centralized data access and the use of mentions. In the article by M. Kircher and P. Jain. Pattern-Oriented Software Architecture, Volume 3: Patterns for Resource Management. J. Wiley and Sons Ltd., 2004. The author explains the significance of patterns in architecture and how they can be identified and leveraged in different levels. It also describes the lower levels of design and the high level organization patterns. This architectural patterns are a mechanism that does not allow behaviors to be abstracted, defined, analyzed so that they can be implemented in the generic behavior. These pattern based design templates act as design accelerators. The examples of architectural patterns are used for security – identification purposes, centralized identity and single sign on (M. Kircher and P. Jain 48). It is also used for integration. For example, B2B gateway and enterprise service bus. An imperative role of an architect is to use their experience and validate solutions from different levels. The patterns allow architects to solve problems through the use of patterns that increase productivity aspects, change management aspects and government aspects. D. C. Schmidt, M. Stal, H. Rohnert, and F. Buschmann. Patterns for Concurrentand Distributed Objects. Pattern-Oriented Software Architecture. J. Wiley and Sons Ltd., 2000. It discusses the value of using patterns for architectures which can be used in a more abstract fashion. This requirement can be placed and mapped across the patterns thus using a gap analysis approach. The important aspect is to ensure that the patterns define the architects requirements and provide clarification that are not covered by other architectural gaps (D. C. Schmidt 53). One useful advantage of pattern based designs is when it occurs with a product platform change. This article gives a detailed design aspect of a pattern that would evolve in order to maximize the use of the supporting platforms. Work cited Christopher Alexander The timeless Way of building New York Wiley and Sons 2009. Print. D. C. Schmidt, M. Stal, H. Rohnert, and F. Buschmann. Patterns for Concurrentand Distributed Objects. Pattern-Oriented Software Architecture. J. Wiley and Sons Ltd., 2000 De Boer , R, C and Jansen A, Architectural knowledge: Getting the core : Quality of Software Architectures. pp.197-214 2008. Frank Buschmann and Kevlin Henney. Explicit interface and object manager.In Proceedings of 8th European Conference on Pattern Languages of Programs (EuroPlop 2003), Irsee, Germany, July. 2003. M. Kircher and P. Jain. Pattern-Oriented Software Architecture, Volume 3: Patterns for Resource Management. J. Wiley and Sons Ltd., 2004 M.A Ali Babar. T. Dingsoyr. P. Lago. H. Van Vliet. Software Architecture Knowledge Management . Springer Velrage 2009. Paul Clements, Felix Bachmann, Len Bass, David Garlan, James Ivers, ReedLittle, Robert Nord, and Judith Stafford. Documenting Software Architectures: Views and Beyond. Addison-Wesley, 2002 Read More