Business Model

The business model defines the goals and context of the business in funding the application. Some of the questions about your application this model answers are:

What are the business requirements for this project?
What business objectives/features must it provide?
What level of investment will provide the best financial return?
How fast must the project be delivered?
How expensive can it be to deploy?
What platforms must it support?
How many users must have access to it concurrently?
How important is security?
How reliable must it be?
How long until this release is replaced or updated?
How quickly must new business policies or end user needs be incorporated into new updates?

In an ideal scenario, implementing an enterprise application architecture begins by defining the business requirements embodied in the business model.

How the business model interacts with other models

As the diagram in the Enterprise Application Model shows, the business model directly interacts with the user model, the logical model, and the technology model. The following table characterizes these interactions and gives brief examples of each.

Sub-model	How the business model relates to it	Example
User model	Determines who will use the application, their skill levels, and their desktop configuration.	An application that must be used by inexperienced personnel must be highly intuitive and well-documented.
Logical model	Sets policies about how business assets must be managed. These policies are reflected in logical business rules.	Business policies determine how shipping, inventory, and sales must respond to new orders.
Technology model	Determines or constrains the technology needed to satisfy business requirements.	A business requirement to direct market the company’s products through electronic commerce mandates Internet technology.

Since the development model permeates all of the Enterprise sub-models, there are no "typical" interactions because you must account for every design and implementation decision in the development model.

You should note that each of these interactions works both ways For example, the cost and capacity of new modems may limit the number of customers a business will be able to serve with its new Internet-based direct marketing application. In this case the technology model might force goals and requirements of the business model to be reassessed.

These business model interactions are examined in greater detail in "Identifying Business Requirements," in Chapter 3, “Creating the Application Architecture.”

How the Internet affects the business model

Examples of the way the Internet has affected the business model include:

The opportunity to write software that can run without changes on multiple platforms (although with varying degrees of compatibility and reliability). To achieve this benefit, however, you may have to accept the cost of testing your application on many platforms, virtual machines, and Internet browsers.
The opportunity to publish vast amounts of information very inexpensively, increasing product visibility and sales while providing a powerful mechanism to decrease product support costs.
The ability to deploy some kinds of "lightly-interactive" applications by using the deployment capabilities of Internet servers, thereby reducing deployment costs.
The need to protect corporate security from malicious Internet Web servers and the risk of Internet delivered viruses or non-sanctioned components. Businesses must be much more careful about links from their corporate LAN to the external world.

For more information The business model is explored in greater depth in "Identifying Business Requirements," in Chapter 3, “Tools for Enterprise Application Design.”