From the Business Models to the Systems

One advantage of our approach to business modeling is its clear and concise way of showing dependencies between business and system models. Figure 8-3 shows this relationship.

Figure 8-3. From the business models to the system models

Business Models and Actors of the System

To identify information-system use cases, begin with the business workers in the business object model. For each business worker, identify a candidate system actor. For each business use case the business actor participates in, create a candidate system use case. For example, see Figure 8-4.

Figure 8-4. You can derive candidate system actors and system use cases based on business models of a bank.

Automated Business Workers

If you are aiming to build a system that automates a set of business processes completely, which is the case if you are, for example, building an e-commerce application, it is no longer the business worker who will become the system actor. It is instead the business actor who will communicate directly with the system and act as system actor.

You are in effect changing the way business is performed when building an application of this kind. Responsibilities of the business worker will be moved to the business actor. For example, see Figure 8-5.

Figure 8-5. Completely automating business workers will change the way the business process is realized and also how you find system actors and use cases.

Business Models and Entity Classes in the Analysis Model

A business entity that is to be managed by an information system will correspond to an entity in the analysis model of the information system. Some attributes of the business entity might also correspond to entities in the information-system model. A business entity can be accessed by several business workers. Consequently, the corresponding entities in the system can participate in several information-system use cases. For example, see Figure 8-6.

Figure 8-6. The business entities customer profile, account, and loan are all for automation.

Using the Business Analysis Model for Resource Planning

If you intend to use the business object model for resource planning or as a basis for simulation, you will need to update to reflect the type of resources used to implement the business workers and artifacts. You need to modify so that each business worker and business entity is implemented by only one type of resource (see Figure 8-7). If you are aiming at reengineering the business process, you should not consider resources in the first iteration of your business object model because that tends to make you focus on the existing solutions rather than identify problems that can be solved with new kinds of solutions. For instance, in the banking example, we decided to update the business object model to use it for resource planning.

Figure 8-7. The business workers are modified to reflect the automation.

Other Sources for Requirements on Systems

There are many sources of knowledge about ”and requirements for ”the information system outside the business model. Examples of sources include:

• Users of the information systems that you have not modeled in the business model ” for example, the system administrator, who is a user of the information system that is (usually) not represented in the business model

• Strategies that the business as a whole has decided on ” for example, regarding IT, reuse, compatibility, and quality

• Any legacy considerations

• Timing and coordination with other projects

• Trends in the business's own industry and in the IT industry

Business Models and System Architecture

From an architectural perspective, having business models in place is particularly useful if your intent is to build one of the following kinds of system:

• Customized systems for one or more companies in a particular type of industry (e.g., banks, insurance companies)

• A family of applications for the open market (e.g., order-handling systems, billing systems, air traffic control systems)

The business models would give input to the use-case view and the logical view as presented in the analysis model. You would also be able to find key mechanisms at the analysis level (analysis mechanisms).