In developing backward-chaining systems, you should undergo several tasks or steps in order to have a better solution and you may have a better design in your system. The tasks or steps to be followed are as follows.

Defining the Problem

Before performing any task in developing backward-chaining system first you should define the problem or learn about the problem. What is your problem all about?

In the question raised above this can be answered by looking or finding information about the problem, and by doing this you can get information through reports, documents and books. These are good sources of information that can be used in developing the system, but these are just for starting point. For most projects you will need the help of a real expert. And discussing the problem to the expert he can give considerable information about the problem and insight on how we might design the system and different approaches on problem solving might also be discussed. Having this information from an expert we can now then proceed to the next important step when designing a backward-chaining system – the goals.

Defining the Goals

The next step is that you need to define the goals. Every backward-chaining system needs at least one goal to get started. By defining the goals this may help you start from the right track and end on the expected track and this may avoid you from being mislead from the real problem. And also by defining the goals in making the backward-chaining system you may also dedicate your time and focus on the part that greatly needs consideration.

Designing the Goal Rules

The third step is designing the Goal Rules; for each goal in our system must have at least one rule or goal rule that can conclude it. You design the goal rule the same way as any other type of rule. That is you look for necessary preconditions to satisfy the rule’s conclusions. Let us say that we call the first goal as portfolio1 and setting up the goal rule is necessary in order to attain the goal and preconditions or rules are needed. Such as IF precondition1 AND precondition2 THEN protfolio1. With the goal portfolio1 is attained but undergo first the two preconditions. The goal rules also have decision table to make and help the decision making with this rules and testing for goal rules are also made.

Expanding the System

The fourth step is expanding the system; and at this point the system already has set of goals and rules. It is totally functioning but not very intelligent. There are two most common ways to expand the knowledge of the system and these expansion techniques are – broadening or deepening the systems knowledge which we teach the system about additional issues and the other one is giving a deeper understanding about the problem which we teach the system more about the issues it already know about.

Refining the System

The fifth step is refining the system; and hear at this point, we have fully functional system the needs our initial objectives. However, there are several additional features we can add to the system that will enhance both its performance and maintenance.

Design the Interface

The sixth step is designing the interface; this step is also very important because the users view your expert system through the system’s interface. To a large extent, the acceptance of your system will depend on how well this interface accommodates the needs of the user. And also if the interface is not as easy and pleasing as expected so even that your expert system is very good the user may not be willing to choose in using your expert system.

System Evaluation

The final step is system evaluation; at this point the prototype system is complete. All of the rules are coded in the system and we assume that the interface is designed according to the recommendations given on the previous sections. So now we are ready for the evaluation of the system, and this is done by making some questions to the expert and tests the system with sample inputs and sees if the system is really running properly. This step is also important so that if there is some recommendations made in evaluation this can be done as soon as possible.