Define your Business Rules


The first step when building a database is to define your “Business Rules”. Every business is different, and consequently, every business has its own set of business rules. Business rules dictate how your business should operate and the database should be designed to enforce these rules. Business rules are often based on the answers to questions such as:

  • Who is able to initiate a purchase order?
  • Who needs to approve a purchase order?
  • What is the minimum balance for an inventory item before you reorder?
  • What reports should be limited to management only?

It is possible that you are a one-person company and therefore do not require many rules. However, it is often best to think ahead and look at where your company might be in a few years time and what your requirements might be then. You could sit down and write these rules out on a piece of paper, but fortunately, there are simpler solutions. A solution worth considering is to create “use case diagrams” and “flowcharts” to help define these rules.

What are Use Case Diagrams?


A use case diagram consists of people, objects, and actions. What you are trying to do is show someone, through your diagram, how your business is structured, or should be structured. Let’s start with a fairly simple example.

This diagram shows what actions an employee is allowed to perform within your database or website application. You can use “stickmen” to represent people and circles to represent actions. This can be accomplished by drawing on a piece of paper, or you could use a program like “powerpoint”.

A second example might be to show the actions that a customer might take, such as browsing the company catalog, managing their account, or placing an order.

You can also use rectangles to represent objects in your diagrams. An object might be an invoice, a purchase order, a car, a building, or a bank account.

How do flowcharts work?


A flowchart is another diagram which can show actions. It also has branching, which means that a workflow can take several different paths, dependent on the answers to certain questions.

The questions posed in a flowchart are ones where the answer is black or white, a YES/NO, or TRUE/FALSE type of answer. If the answer is YES then you branch in one direction and if the answer is NO you branch in another direction.

In this diagram there are several actions shown i.e. “check time”, “take bus”, “take subway”. To determine how the student should go to school, we need to look at the current time. The question “Before 7am?” can only be answered with YES or NO, and the action to take is dependent on the answer.

I think once you start to use flowcharts you will find that they are a great tool for displaying the flow of information within your business and extremely helpful in defining your business rules.

Working Together

Some people might find the idea of creating “use case” and “flowchart” diagrams a bit intimidating, but that is what we’re here for. Datacon Data Services will sit down with you, to help you determine what you actually need and want.  We will try to make the process of creating a database or designing a system as simple as possible. The main point is for us to communicate and exchange ideas, so that we can build the best system for both you and your company.