Artifacts > Business Modeling Artifact Set > Business Object Model... > Business Object Model > Guidelines > Going from Business Models to Systems


Introduction To top of page

The approach to business modeling presented in the Rational Unified Process includes a concise and straightforward way to generate requirements for supporting business tools or systems. A good understanding of business processes is important for building the right systems. Even more value is added if you use people's roles and responsibilities, as well as definitions of what "things" are handled by the business as a basis for building the system. It’s from this more internal view of the business, captured in a business object model, that you can see the tightest link to what the models of the system needs to look like.

The relation between models of the business and models of a supporting information system

Business Models and System Architecture To top of page

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

  • Customized systems for one or more companies in a particular type of industry, such as banks and insurance companies.
  • A family of applications for the open market, such as order handling systems, billing systems, and air-traffic control systems.

The business models give input to the use-case view and the logical view as presented in the analysis model. You can also find key mechanisms at the analysis level, which are referred to as analysis mechanisms.

The following should be considered:

  • For each business use case that will be supported by the system, identify a subsystem in the analysis model. This subsystem is in the application layer and is considered a first prototype iteration. For example, if you have an Order process and a Billing process in your business use-case model, identify an Order subsystem and a Billing subsystem in the application layer of your analysis model. You may argue that Order and Billing are separate systems. Well, that’s a matter of scope. If you’re considering all of your business tools as one system with several applications that share architecture, Order and Billing would be application subsystems. If your scope is to build an Order Management application only, then Order Management would be your system and the recommendation above would not make sense. It only makes sense if your scope is such that you consider all business tools in your organization as one system.
  • For each business worker supported by the system, identify use cases that represent what is to be automated.
  • For each business entity supported by the system, identify entity classes in the analysis model. Some of these are candidates for being considered as key mechanisms, the component entities, in the system.
  • For clusters of business entities—a group of business entities that are used solely within one business use case or a group of otherwise closely related business entities—create a subsystem in the business specific layer.

In a four-layered system architecture, business models give input to the top two layers

Business Models and Actors to the System To top of page

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.

To identify information-system use cases, begin with the business workers in the business object model. For each business worker, perform the following steps:

  • Decide if the business worker will use the information system.
  • If so, identify an actor for the information system in the information system’s use-case model. Give the actor the same name as the business worker.
  • For each business use case in which the business worker participates, create a system use case.
  • Repeat these steps for all business workers.


Based on business models of a bank, you can derive candidate system actors and system use cases.

Automated Business Workers To top of page

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


When building an e-commerce site for a bank, you will be modifying the way the process is realized.

  • Responsibilities of the Clerk will be moved to the Customer.

  • Create a system actor Customer corresponding to the business actor Customer.

  • Remove the system actor Clerk.

  • Modify the system use case Money Transaction 1 to work with the system actor Customer, instead of Clerk.

Completely automating business workers changes the way the business process is realized, as well as how you find system actors and use cases

Business Models and Entity Classes in the Analysis Model To top of page

For each business entity, create a class in the system's analysis model

A business entity to be managed by an information system will correspond to an entity in the analysis model of the information system. In some cases, however, it might be suitable to let attributes of the business entity correspond to entities in the information-system model. Several business workers can access a business entity. Consequently, the corresponding entities in the system can participate in several information-system use cases.


The business entities Customer Profile, Account, and Loan are all candidates for automation.

Interaction between Business Workers Translated to System Requirements To top of page

How should you interpret a link between workers in the business model? You must find out how the information systems can support the communicating workers. An information system can eliminate the need to transport information between workers by making the information available in the information system.

Using the Business Object Model for Resource Planning To top of page

If you intend to use the business object model for resource planning or as a basis for simulation, you will need to update it to reflect what types of resources are used. You need to modify it so that each business worker and business entity is implemented by only one type of resource. If your aim is to re-engineer the business process, in the first iteration of your business object model, you should not consider resources. Doing so tends to make you focus on the already existing solutions, rather than on identifying problems that can be solved with new kinds of solutions. Here's an example of a procedure to consider:

  • In a first iteration of the business object model, work without considering the resources or the systems that will be used to implement the business.
  • Discuss what can be automated.
  • Discuss how automation can change the business process and start sketching out a system use-case model and system requirements.
  • In a second iteration to the business object model, update it to reflect resources used and what is to be automated.
    • Some business workers will be tagged as automated workers.
    • Some business workers will be split into two—one automated, the other one not.
    • Parts of two business workers may be partitioned out to a new automated worker.
    • Parts of a business worker’s responsibility may be moved outside of the organization to become the responsibility of a business actor.


In the banking example, we decided to update the business object model in order to use it for resource planning.

  • The Clerk business worker is completely automated and becomes an Automated Clerk. The bank will only do on-line banking.

  • The Loan Specialist is partly automated, and is split into an Automated Loan Specialist and a Loan Specialist.

The business workers are modified to reflect automation

Summary Table To top of page

The following table summarizes the relationship between the business models and the system models.

System Models How to find candidates, using information in the business models Business Models
Actor Actor candidates are found among business workers. Business worker
Actor Other actor candidates are found among the different business actors (customers, vendors) that will directly use the system. Business actor
Use case Use-case candidates are found among business-workers’ operations. Look for operations, and areas of responsibility, that involve interactions with the information system. Ideally one information system use case supports all the business worker’s operations within one business model use-case realization. Business workers’ operations
Entity class Entity class candidates are found among business entities. Look for business entities that should be maintained or represented in the information system. Business entity
Entity class Entity class candidates are found among attributes in the business object model. Look for attributes that should be maintained or represented in the information system. Attributes
Relationships between entity classes Relationships between business entities often indicate a corresponding relationship between the classes in the information system model. Relationships between business entities

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