Architecture Descriptions

You come to realise that the architecture of the plant is an abstract concept, instantiated by numerous different types of descriptions. When you were asked to describe the architecture, you should have been told what the description was to be used for and who was going to use it, as the appropriate descriptions depend on the view one takes of the plant. 

In some industries or jurisdictions, agreement has been reached on which views are required for their purposes and which descriptions are required to document each view such an agreed set of views and descriptions is called a. framework. Perhaps the best known one is the US Department of Defence Architecture 

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An architectural description is an abstraction there are many such abstractions that contribute to understanding a system, each one focused on one aspect and omitting other details. As with any model, there is some definition of conformance—that is, does a given implementation conform to that architecture Some views are more focused on the design and development-time activities others are relevant when you re testing or running the system still others focus on deployment and upgrade activities. Table 12.1 shows some useful architectural views and the system parts each one focuses on. 

Architecture Description Languages (ADLs) have been receiving much study recently. Important work includes the ABLE project (with the language WRIGHT) [Able] and Rapide [Luckham95],... 

A complete architectural description of ammonia needs to include the torsion angle t, the angle formed between the H —N—plane and the H —N—plane, which has a value of 119.14°. 

Level 2 Architecture. Description of the gross arrangement of secondary structures in 3D space independent of their connectivity. 

Only protein structures solved to resolution better than 3.0 A from the Protein Data Bank are considered. The 3D templates are generated with CORA (Conserved Residue Attributes) for recognition of structural relatives in each fold group (Orengo, 1999). The CATH Architectural descriptions that denote the arrangements of secondary structures are given in Table 12.2. 

Furnish CATH architecture descriptions for the following proteins ... 

Investigations of static structures include architectural descriptions, comparisons and classifications, and identifications of recurrent patterns such as supersecondary structures. Examples include the classification of types of proteins by Levitt and Chothia (28), the hierarchical analysis of protein structures by Rose (29), or the comparison of globin structures by Lesk and Chothia (30). 

The research reported in this paper focused on the design of a syngas cluster and infrastructure taking into account technical, economic and institutional requirements. The design approach was based upon an architecture paradigm [1] An adequate system architecture description must cover whatever aspects of cost, behavior, performance, organization, physical structure or other elements that need to be added to clarify the clients priorities. ... 

The construction of a precise and formal architectural description facilitates the detection of general system parts to build up a framework of reusable software components [43, 44], e.g. for tool wrapping software product reuse). Also, software process reuse is fostered in the sense that specific components can be generated automatically from specifications. 

Concepts for architecture modeling (Subsect. 5.7.2). Firstly, in order to define a suitable vocabulary for architecture modeling an adequate architecture description language is required. Such a language [331] defines the basic modeling idioms, like modules, subsystems, components, interfaces, and relationships, from which an architecture is built. 

This subsection demonstrates how the coarse-grained architecture of the design environment (cf. Fig. 5.55) is gradually refined towards a detailed architecture description, considering aspects like (i) decomposing components, (ii) introducing wrappers, and (iii) distributing components via certain middleware techniques. 

Garlan, D., Monroe, R., Wile, D. ACME An architecture description interchange language. In Proceedings of the 1997 Conference of the Centre for Advanced Studies on Collaborative Research (CASCON 97), Toronto, Ontario, Canada, pp. 169-183 (1997)... 

IEEE, Institute for Electrical and Electronics Engineering IEEE recommended practice for architectural description for software-intensive systems. IEEE Standard 1471-2000 (2000)... 

For each software module, the specification defines module architecture, descriptions, interfaces and relationships (events, timers, handshaking). Each module can be further decomposed into... 

Modeling method According to the architecture descriptions, designers obtain the descriptions of all the states in an enterprise by abstracting the business function, business data, and business period. 

By selecting and deselecting options in the architecture description, it was also possible to perform a first-order assessment of the relative importance of each architectural option in determining the Overall Residual Safety-Risk Metric. 

Fault tolerance techniques aiming to detect transient effects can be mainly divided in three broad categories (1) software-based techniques, (2) hardware-based techniques and (3) l brid techniques. Fault tolerance techniques can be applied at different levels of implementation, starting from the software level down to the architecture description level, the logical and transistor level, until the layout level. In this book, we will focus on hybrid techniques applied at software level. 

SAV Coding Standards - describe the programming languages, methods, rules and tools used to code the SAV from the high- and low-level SAV requirements and SAV architecture description. 

The same problem is compounded in architectural descriptions, where DDD uses recursive networks of streams to model synchronous hardware. Animation of streams in Scheme is done using function closures and continuations to implement call-by-need behavior. Neither of these higher-order objects can be expressed directly in Nqthm, nor can nonterminating function systems. 

Explaining all processes and principles of architecture design would go beyond the scope of this chapter. However, apart from ISO/IEC 42010 (2011) [63] that provides standards for architecture description for systems and software, there are well-known commercial, defense and government frameworks [64] that can be used as guidance when elaborating enterprise architecture ... 

Acme Interchanges architecture description information between ADLs. 

Aesop Is used to model style-specific architecture descriptions, also provides support for designing custom architecture styles. 

C2 Supports architecture description of highly-distributed, evolvable, and dynamic systems. 

Medvidovic, N. Taylor, R.N., "A classification and comparison framework for software architecture description languages," Software Engineering, IEEE Transactions on, vol.26, no.l, pp.70-93, Jan 2000... 

There has been an ongoing drive for reasoning about reliability at the architectural level. Consequently, Architectural Description Languages (ADLs) introduce new notations. 

Gacek, C., De Lemos, R. Architectural Description of Dependable Software Systems. In Besnard, D., Gacek, C., Jones, C. (eds.) Proceedings of Structure for Dependability Computer-Based Systems from an Interdisciplinary Perspective, pp. 127-142. Springer, Heidelberg (2006)... 

To gain the knowledge about the architecture of the whole OS in terms of software component composition and bindings, we can use Architecture Description Language [12] as the specification of the architecture of the system. This language has the possibility to capture interface types (with method signatures), primitive components (in terms of provided and required interfaces), composite components (an architectural compositions of primitive components) and the bindings between the respective interfaces of the components. 

It is extremely important to define the right role of the behavior and architecture description. A flawed approach would be to reverse-engineer this description from the source code (either manually or via some sophisticated tool) and then verify the compliance between the description and the implementation. However, different directions can give more interesting results ... 

Description as specification. Behavior and architecture description created independently on the source code serves the role of specification. This has the following primary goals of formal verification ... 

Vertical compliance. Also called substituability. The goal is to check whether it is possible to replace a set of primitive components that are nested inside a composite component by the composite component itself. In other words, this compliance can answer the question whether the architecture description of the system is sound with respect to the hierarchical composition of the components. 

Specification and implementation compliance. Using various means of generating artificial environments for an isolated component a checker is able to partially answer the question whether the implementation of the component is an instantiation of the component specification. Description as abstraction. Generating the behavior and architecture description from the source code by means of abstract interpretation can serve the purpose of verifying various properties of the implementation such as invariants, preconditions and postconditions. This is similar to static verification, but on the level of component interfaces. 

We have created an architecture description in ADL language derived from SOFA ADL [12] for the majority of the HelenOS components and created the Behavior Protocol specification of these components. Both descriptions were created independently, not by reverse-engineering the existing source code. The architecture... 

Both the architecture and behavior description is readily available as part of the source code repository of HelenOS, including tools which can preprocess the Behavior Protocols according to the architecture description and create an output suitable for bp2promela checker [2]. 

We have not started to generate code from the architecture description so far because of time constrains. However, we believe that this is a very promising way to go and provide reasonable guarantees about the compliance between the specification and the implementation. 

Oplustil, T. Inheritance in Architecture Description Languages. In Reviewed section of Proceedings of the Week of Doctoral Students 2003 conference (WDS 2003), Charles University, Prague, Czech Republic, vol. 2003, pp. 124-131 (2003)... 

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