Section 14.1. Project Scope
|
14.1. Project ScopeDeutsche Post sees its SOA as a business-oriented IT strategy. The main objective is to standardize access to functionality and to ensure reusability. The SBB (Service Backbone)the major outcome of the infrastructure developmentis described in detail here. When starting to restructure its IT landscape, Deutsche Post followed the approach summarized in Figure 14-1. Figure 14-1. Deutsche Post's use of a Business Domain Model to get from business processes to IT applications. The first step was the creation of a business requirement evaluation, which led to the redesign of many business processes according to the analyzed input-output relations. The Business Domain Model (BDM) that was designed in further process steps is comprised of modular components. Closely related functionalities and data are bundled in domains.[2]
14.1.1. BUSINESS IMPACTOne of the most important benefits of Deutsche Post's BDM is the fact that it enables a view of IT applications from the business perspective by providing appropriate representation of business-oriented components, their interfaces, and interconnections. Deutsche Post utilizes an insightful metaphor to promote its SOA internally (see [HBa04]). Deutsche Post compares the concept of its SOA to a map of a city. BDM's high-level components are called domains. They describe reasonably separated components, which contain the main business logic. Deutsche Post compares these domains to different districts of a city. Every district (such as airport, residential area, industry parks, etc.) has a clearly defined purpose. The urban infrastructure (such as streets, and electricity and water supply) connects the different districts to each other and is compared to Deutsche Post's Service Backbone, which provides access to the business logic encapsulated by the domains. Figure 14-2 shows the Business Domain Model used at Deutsche Post and its use of the domain concept. As the main components of this construct, domains contain modularly defined functionality and thus enable the support of business processes and the underlying data. Figure 14-2. Deutsche Post's Business Domain Model with domains. According to Deutsche Post's motivation paper [HBa04], the main characteristics of domains are as follows:
One of the first services to be realized was Customer Management,[3] that is, management of core customer data. This service was chosen because it is widely used within Deutsche Post. It offers about a dozen operations, including operations for inserting, searching for, or deleting customer data. Currently, there are around ten service consumers of the customer-management service with a resulting workload of approximately 0.5 million calls per month.
Another widely used and visible service is Complaint Management.[4] Although only one service consumer uses the implemented service, this service consumer is connected to more than 1,000 clients.
Altogether, the business services implemented so far are used by a double-digit number of applications, issuing approximately 2 million service calls per month. In addition to services providing business functionality, the SOA at present also contains about a dozen technical services with altogether 80 service operations. In general, the focus of the implemented business services is on intra-corporate use. Deutsche Post's SOA was developed for Division Mail, which is very business- and IT-oriented and open for innovation. A dedicated IT business unit was set up at Division Mail that is, among other things, responsible for the implementation of both the business services and the underlying infrastructure (the Service Backbone). In addition to the intra-corporate usage of the SOA, there are also some pilot projects exploring the external use of the implemented services. These pilot projects reuse the services' interfaces and enhance them by adding an extra layer based on WSDL (Web Services Description Language), thereby turning them into full-fledged Web services.[5]
Moreover, based on the success of Deutsche Post's SOA at Division Mail, a rollout for DHL (another major brand of Deutsche Post) is currently in preparation. The idea is to reuse the methodology developed at Division Mail and the technical infrastructure (i.e., the Service Backbone). However, services will be developed by DHL themselves. 14.1.2. TECHNOLOGY IMPACTDeutsche Post's SOA has a strong technical focus on Java applications. Although there is an adapter to C++ and JDBC, the support of heterogeneous environments is not in Deutsche Post's main focus. At Deutsche Post, the integration infrastructure needed for an SOA is realized with the Service Backbone (SBB). Its main functionality is to receive service calls from service consumers and to forward them to dedicated service providers (see Figure 14-4). The key features of the SBB are (see [HBa04]):
Figure 14-4. A service call using SBB functionality.
The purpose of the SBB is purely technical. The entire business logic of the SOA is placed in domains. Existing custom-built applications and off-the-shelf packages like SAP are encapsulated according to the standards of the SBB in a way that their functionality can easily be used by SBB participants. The whole philosophy of SBB is federal because the business is federal, too. Data transformation is also handled with care: To ensure that no business logic is incorporated directly into the Service Backbone, the necessary transformation is performed by using mapping tables. The SBB only provides the basic functionality for the execution of these transformations. The contents of the tables, that is, the actual mappings, are maintained on the business level, however, in the service implementation of the domain. The respective business units enter the required information into the mapping tables and check table updates into the SBB runtime environment.[6]
|
|
EAN: 2147483647
Pages: 142