The specification of these functions can be informal, using English text or formal, using syntactic or semantic specifications of functions. While informal descriptions are mostly done at the coarse business level, more precise speci- fications are required in the software layer when it comes to implementation of certain functions using information systems.
The investigation and proper representation of data in business processes is important, because decisions made during a business process depend on particular data values. Also data dependencies between activities need to be taken into account in process design, to avoid situations in which a function requires certain data not available at that time.
The proper representation of the organizational structure of a company is an important requirement. Activities in the business process can then be associated with particular roles or departments in the organization. Many ac- tivities in a business process are performed by or with the assistance of infor- mation systems. The operational information technology landscape, i.e., the information systems, their relationships, and their programming interfaces, needs to be represented to use the functionality provided by the information systems.
Process modelling defines the glue between the subdomains. A process model relates functions of a business process with execution constraints, so that, for instance, the ordering and conditional execution of functions can be specified. Data aspects are covered because particular process instances may depend on the structure and value of data involved in a particular busi- ness process. For example, in a credit approval business process, the type of approval depends on the credit amount requested. In addition, data depen- dencies between activities need to be taken into account in process model design.
Supplier Value Chain Supplier Value
Chain Value System
Value Chain
Supplier Value Chains
Enterprise E 1
*
Business Function 1
*
OrderManagement 1
*
GetOrder CheckOrder
AnalyzeOrder SimpleCheck AdvCheck Marketing and
Sales Operations
Enterprise E
Supplier Value Chain Supplier Value
Chain Channel Value
Chains
Fig. 3.4.Functional decomposition from value chain to business functions
The functional decomposition of the value chain of enterprise E is exem- plified for one particular path of functions in the marketing and sales top-level business function. Among many other functions, marketing and sales includes a business function,OrderManagement, that contains functions related to the management of incoming orders. Order management is decomposed further into business functions for getting and checking orders. To check orders, they need to be analyzed, and there are functions for simple and advanced checking of orders.
As shown in Figure 3.4, there are different symbols for business functions and for functions of the finest granularity: business functions are represented by rectangles, while functions of the finest granularity are represented by rectangles with rounded corners. Functions at the leaf level of the functional decomposition are also called activities.
Traditionally, functional decomposition was used to describe enterprises based on the functions they perform. As discussed in Chapter 1, concentrating on the functions an enterprise performs and neglecting their interplay falls short of properly representing how enterprises work. Therefore, functional decomposition is used as first step in the representation of enterprises based on business processes.
Operational business processes relate activities to each other by introduc- ing execution constraints between them. In principle, relating functions to business processes can be applied for different granularities of business func- tions. In case high-level business functions are considered, a textual specifica- tion of the process is used, since concrete execution constraints between their constituents are not relevant in coarse-grained business functions.
Consider, for instance, the business functions incoming logistics and oper- ations. At this very coarse level of functionality, no ordering of these business functions is feasible: both business functions are performed concurrently, and only at a lower level of granularity does a concrete ordering make sense.
For instance, when the operations business function orders additional ma- terial, then there are concrete activities that have a concrete ordering. Within operations, an internal order is created and sent to incoming logistics. On ar- rival of this order, raw material is provided to operations. In case no raw ma- terial is available at the manufacturing company, an external order is created and sent to a supplier of the raw material. Therefore, business processes relate fine-grained business functions, typically the leaves of the business function decomposition tree. Figure 2.13 represents how high-level business functions can be described.
Business Function OrderManagement
1
*
GetOrder CheckOrder
Business Process 1
1..*
AnalyzeOrder
SimpleCheck
AdvCheck
Activity 1
*
AnalyzeOrder
AnalyzeOrder SimpleCheck AdvCheck
Fig. 3.5.Business functions of small granularity are organized as a business process
In the example shown in Figure 3.5, the activities AnalyzeOrder, Sim- pleCheck, and advanced check (AdvCheck) are related to each other by execu- tion constraints. The sample business process starts with analyzing the order, and then conducting either a simple check or an advanced check depending on the decision made during process execution. This process has a dedicated start event and a dedicated end event. The business process is started once the start event occurs; when it completes, an end event occurs. Events play a crucial role when interrelationships between business processes are expressed.
A particular business function of higher granularity (CheckOrder) consists of fine-grained activities, which are related by execution constraints. However, the check order business function (and the business process that realizes it) is related to other business functions and their respective business processes.
An example showing this situation is displayed in Figure 3.6, where a part of the value chain is shown, in particular, the business functionsReceive Request, Request Analysis, and Quota Management are shown. Since there is a strict ordering between these business functions, an execution ordering relation is represented.
Receive
Request Request
Analysis Quota Mgt
Fig. 3.6.Related business processes, high-level view
TheReceive Request business function is realized by the business process shown in Figure 3.7, as are the business processes realizing the other business functions. The start and end events of the business processes are connected as shown in the figure, so the execution ordering constraints of the business functions are realized.
After the business process related to receiving the request is processed, it generates its end event. This end event is the signal for starting the second business process, related to request analysis. Finally, the quota is prepared and the business process completes. This discussion shows that business pro- cesses at a lower level can be identified, as well as business processes at a higher level, i.e., those relating business functions. The connections between the business processes are represented by link events, discussed in more detail in Section 4.7.
The overall organization of these levels is depicted in Figure 3.8. At the left hand side of this figure a UML structure diagram provides a conceptual model of the entities involved. To recapitulate, each enterprise is represented by a value chain, which consists of coarse-grained business functions that are decomposed into smaller-grained business functions, realizing a functional
Receive Request
Store Request
Send Request Ack
SendQuote
ReceiveOrder
ReceiveCancel Prepare
Request Analysis
Request Analysis
Fig. 3.7.Related business processes, detailled view
decomposition. Activities are functions of the finest granularity; they are the building blocks of operational business processes.
When a business process is started, the business functions that it contains need to be executed. Therefore, each activity in a business process requires an implementation. The implementation of an activity can be based on function- ality provided by information systems, such as registering a new customer or reserving a flight. However, an activity implementation can also be provided by a knowledge worker without using information systems.
Definition 3.1 A functional decomposition of coarse-grained business func- tions to fine-granular activities defines thefunctional perspectiveof a business
process.