Architectures and architectural knowledge are introduced through four fundamental or core properties. The first fundamental issue when an object or a system is approached from the architectural perspective is to understand that systems can and do comprise more than one structure, and none of these structures can irrefutably claim to be an architecture. This means that when there are more than one structure, there are also more than one type of elements, more than one type of interactions and also more than one type of context
34
(Bass et al., 2003). In other words, there is no single service architecture or even information system architecture; there are architectures from different perspectives instead. The second fundamental property of architecture is related to its existence independently from its descriptions, and the third the behavior of each element as part of the architecture insofar as that behavior can be observed or discerned from the point of view of another element (ibid.). This aspect was already introduced in the first section of the dissertation by stating that architecture describes the public side of the system, but hides the internal logic. Bass et al. (2003) propose also a fourth property by stating that when the architecture for a system is a good one or a bad one, it will allow or prevent the system from meeting its behavioral, performance, and life-cycle requirements. These software-oriented definitions highlight the design tradition in the software context: architecture is a well-known step in a software design project.
Booch (2008) repeats the common slogan in the architectural field by which all architectures are designs, but all designs are not architectures. The relationship between two artificial but widely used elements is partly misleading and inconsistent in different fields of literature. In a similar way that architectures and designs are mixed in the literature, architectures are often conceptualized by a very narrow focus as design objects and end results. Baldwin (2010) explains the concept of architectural knowledge as knowledge about the components of a complex system and how they are related. This knowledge can be further divided into three categories: how the system performs its functions, how the components are linked together, including the interfaces, and how the system behaves in both planned and unplanned ways in different environments (ibid.). Henderson and Clark (1990) use the term architectural innovation to describe a change in a product which is based on changing the way the core components of a product are linked together and simultaneously leaving the core design concepts behind the product untouched. They state that though this kind of innovation may destroy the usefulness of the architectural knowledge, it preserves the usefulness of its knowledge about the product components. Kruchten et al. (2006) argue that architectural designs are only one part of architectural knowledge which is used in four core activities: designing a system, guiding a multisite development team, exploited out of system in order to create a new one, and evolving a system. Their conceptualization of the architectural knowledge is design decisions + design. The design decisions can be implicit and undocumented, explicit but undocumented, explicit and explicitly documented (reasoning is missing), and explicit and documented.
In the service context, the research focusing on the architectural perspective is a mixture of elements extracted from the manufacturing context and aspects that are expected to be valid also in services. The aspects that have been reviewed also in the service context (Voss and Hsuan, 2009) consist of the following arguments: Sanchez (1999) takes a systems view by defining an architecture as a system for which designers have specified (i) the way the overall functionalities of the product or process design are decomposed into individual functional components (Baldwin & Clark, 1997) and (ii) the ways in which the individual functional components interact to provide overall functionalities of
35
the system design. Component interactions are generally described in terms of specifications that define the inputs and outputs that cross the interfaces between interacting components. Fixson (2005) sees architecture as having six dimensions— product modularity, component complexity, product platforms, loosely coupled interfaces, component commonality, and the number of components—in process and supply chain domains.
Rechtin (1991) proposes that the architecture of a system is determined through two opposite processes: partitioning and aggregating. While partitioning imposes structure to the design problem by breaking it down into smaller sub-problems, too many partitions make the design intractable. On the other hand, while aggregating similar functions and features helps simplify the design, too much aggregation may cause important details to be left out of the design. Heckl & Moormann (2009, p. 3) define architecture in the service context as follows: “The architecture describes which modules are part of the entire system and with which properties (i.e. functions) they should be endowed.” When these views are compared with the arguments presented by Bass et al. (2003) in the software field, service researchers tend to use the architecture concept in a way equal to the one Bass et al. use architectural structures and views. It is potentially an acceptable way, but most of the studies conducted in the service context do not acknowledge that architecture may be viewed by using different core assumptions, and the fact that there is no single architecture.
A potential limitation in the existing studies has been identified by Frandsen (2012, p. 19) who explains how a pre-designed architecture may not be a relevant concept in the service context: “the architecture rather than being a fixed entity established a priori was indeed described as something which had been subject to major changes during the course of developing and implementing the new processes and systems.” Whether these changes are possible or not, can be characterized through the concepts of open and closed architecture. According to Baldwin (2010), in a system which is governed by an open architecture, the key modules of the system can be imported by external agents, which means that the architecture itself does not have to be redesigned each time when a component or module is imported or removed.
Out of the many aspects that could be explored under the architectural theme, one of the most important elements requires attention: the scope and usage of the architecture. The scope should answer the question: what are the dimensions and boundaries of the architecture? The usage perspective should provide an answer to the questions: who will use the architecture and how will it be used? Voss and Hsuan (2009) propose a layered service architecture with four layers which could be described as a business-oriented service architecture. It consists of an industry layer, a service company/supply chain layer, a service bundle layer and a service package/component layer, and all these layers are architectural views on services. The approach of Voss and Hsuan (2009) shows that even though there is no single architecture in any system, the selected architectural view with its components and interfaces must be positioned somehow in the context where the
36
architecture is applied. Product-level components may include the industry-level interface characteristics but they can hardly be explained using a single-level architecture. This is also how the scope of the architecture is used in this study. The usage aspect is much more difficult to capture. From the usage perspective, considering potential architectures as hierarchical (the same perspective but different level of details) and complementary views (different perspective but the same level of details) offers a potential way of collecting previously separate domains and experts together (Lankhorst, 2005), though it is not an easy task as each domain has its own culture, own models, own guiding principles, and of course its own objectives. Ross et al. (2006) argue that higher-level architectures often cause a feeling as if someone is doing something about complexity without any link to real activities. This argument provides at least two important insights: using architectures and understanding them is not the same as trying to understand visualizations of architectures, and architectures can be used to hide the real logic behind activities which can be used in positive and negative ways. In the service literature the usage perspective related to architectures is even less acknowledged, and even though the researchers apparently have always an idea of a potential user, it is not expressed. Similarly to service design, also architecture or any other system description should not be used too lightly.
In this sub-section the concept of architecture and architectural knowledge were explored and as a result, definitions for further utilization in this study were created by combining the definitions by Baldwin (2010) and Kruchten et al. (2006): architectural knowledge
consists of a design (components, relationships and interfaces), decisions made in the construction of the design, decisions embedded in the design, and description of how the design performs and how the behaviour is dependent on the environment where the design is utilized. This conceptualization is rather long but it covers aspects that have
been concluded or proposed in the existing literature. In the rest of this study, architecture is used in two different ways: i) to describe the structure of architectural knowledge (information object) and ii) to describe the meta-design level object which is used to create architectural knowledge (information processing logic). It is proposed that this type of construction is necessary, as otherwise it can be difficult or even impossible to distinguish the information flows related to service delivery (contextual and substance focused) from the information flows used between service design and service operations.