A business rule is the basic unit of rule processing in a Business Rule Management System (BRMS) and, as such, requires a fundamental understanding. Rules consist of a set of actions and a set of conditions whereby actions are the consequences of each condition statement being satisfied or true. With rare exception, conditions test the property values of objects taken from an object model which itself is gleaned from a Data Dictionary and UML diagrams. See my article on Data Dictionaries for a better understanding on this subject matter.

A simple rule takes the form:

if condition(s)

then actions.

An alternative form includes an else statement where alternate actions are executed in the event that the conditions in the if statement are not satisfied:

if condition(s)

then actions

else alternate_actions

It is not considered a best prectice to write rules via nested if-then-else statements as they tend to be difficult to understand, hard to maintain and even harder to extend as the depth of these statements increases; in other words, adding if statements within a then clause makes it especially hard to determine which if statement was executed when looking at a bucket of rules. Moreoever, how can we determine whether the if or the else statement was satisfied without having to read the rule itself. Rules such as these are often organized into simple rule statements and provided with a name so that when reviewing rule execution logs one can determine which rule fired and not worry about whether the if or else statement was satisfied. Another limitation of this type of rule processing is that it does not take full advantage of rule inferencing and may have a negative performance impact on the Rete engine execution. Take a class with HSG and find out why.

Rule Conditions

You may use the camera application on a regular basis. Taking photos of family gatherings, of the scenery around you, or just a self-photo with you and your friends. But, as you may find out, pressing that picture button on the screen is not the easiest thing to do. You may not hit it when you attempt to press it, or you aren’t sure if you pressed it at all.

In a recent update by Apple, the iPhone can now take photos without the use of that button. Although you may continue to use it, an easier method to take photos would definitely be pressing your volume buttons. When you have everyone situated, and ready to take a picture, you don’t have to move your finger over to the camera button. Just put your finger on one of the volume keys on the left hand side of your phone, and press it, and your iPhone should take the picture! It’s just that easy.

I suspect that many of you are familiar with the term "hard coding a value" whereby the age of an individual or their location is written into the condition (or action) of a business rule (in this case) as shown below:

if customer.age > 21 and customer.city == 'denver'

then ...

Such coding practices are perfectly expectable provided that the conditional values, age and city, never change. They become entirely unacceptable if a need for different values could be anticipated. A classic example of where this practice occurred that caused considerable heartache in the IT industry was the Y2K issue where dates were updated using only the last 2 digits of a four digit number because the first 2 digits were hard-coded to 19 i.e. 1998, 1999. All was well provided that the date did not advance to a time beyond the 1900’s since no one could be certain of what would happen when the millennia arrived (2000). A considerably amount of work (albeit boring) and money, approximately $200 billion, went into revising systems by way of software rewrites and computer chip replacements in order to thwart any detrimental outcomes. It is obvious how a simple change or an assumption can have sweeping consequences.

You may wonder what Y2K has to do with Business Rule Management Systems (BRMS). Well, what if we considered rules themselves to be hard-coded. If we were to write 100s of rules in Java, .NET or whatever language that only worked for a given scenario or assumption, would that not constitute hard-coded logic? By hard-coded, we obviously mean compiled. For example, if a credit card company has a variety of bonus campaigns, each with their own unique list of rules that may change within a week’s time, what would be the most effective way of writing software to deal with these responsibilities?

Visual Studio .NET is one of many tools available at your disposal for web development. But where some programs may focus on HTML coding or graphics, Visual Studio .NET is a complete tool set that can be used to not only create XML web services and ASP web applications, but desktop and mobile applications as well. So what are some features that are included in the latest release?

·         Visual J#. This is most well-known by developers who are well-versed in the language of Java. It is best used when building services via the .NET framework, or when building applications.

·         Smart Device Applications. This enables you to generate, repair, and install applications that can be used on smart phones, PDAs, and other devices.

·         ASP.NET Mobile Design. Allows for building web applications for not only PDAs and mobile phones, but pagers as well. This also allows a designer to manipulate the mobile Web form of an application.