- Business rules approach
Business rulesare abstractions of the policies and practices of a business organization. The Business Rules Approach is a development methodology where rules are in a form that is used by, but does not have to be embedded in business process management systems.
The Business Rules Approach formalizes an enterprise’s critical business rules in a language that managers and technologists understand. Business rules create an unambiguous statement of what a business does with information to decide a proposition. The formal specification becomes information for process and rules engines to run.
The adoption of business rules adds another tier to systems that automate business processes. Compared to traditional systems, this approach has the following major advantages,
* lowers the cost incurred in the modification of business logic
* shortens development time
* rules are externalized and easily shared among multiple applications
* changes can be made faster and with less risk
Business rules represent a natural step in the application of computer technology aimed at enhancing productivity in the workplace. Automated business processes that have business logic embedded inside often take substantial time to change, and such changes can be prone to errors. And in a world where the life cycle of business models has greatly shortened, it has become increasingly critical to be able to adapt to changes in external environments promptly. These needs are addressed by a business rules approach.
Business rules enhances
Business Agility. And the manageability of business processes also increases as rules becomes more accessible.
The programs designed specifically to run business rules are called
rule engines. More complete systems that support the authoring, deployment and management of business rules are called business rules management systems ( BRMSs).
Many commercial rule engines provide the
Rete algorithm, or a proprietary algorithmthat embodies many of the principles of Rete. However there are other execution algorithms such as the sequential algorithm (ILOG and Blaze Advisor terminology), algorithms for evaluating decision tables/trees as well as algorithms tuned for hierarchical XML. The Rete algorithmis a stateful pattern matching algorithm designed to minimize the evaluation of repetitive tests across many objects/attributes and many rules. There are different fields of usage which are best for Rete-based and non-Rete-based execution algorithms. For simple stateless applications, with minimal sharing of conditions across rules, a non-Rete-based execution algorithm (such as the sequential algorithm) may be preferable. For evaluating decision tables and trees an algorithm that exploits the hierarchical relationships between the rule conditions may perform better than a simple Rete or sequential algorithm tuned for discrete rules.
Business rules can be expressed in a way similar to conventional programming languages or in languages resembling natural ones. In some commercial BRMS's rules can also be expressed in user-friendly rule forms such as decision tables and decision trees. Provided with a suitable interface to design or edit decision tables or trees, it is possible for business users to check or change rules directly, with minimal IT involvement.
When rules are expressed in a way similar to a natural language, it is necessary to first define a vocabulary to be used, which contains words and expressions that correspond to business objects and conditions and operations involving them. To make the rules executable by a rule engine, it is also necessary to implement the operations and conditions in a
programming language. With a defined and implemented vocabulary, it is relatively easy to write rules in a BRMS. Changes can also be made quickly as long as they can be expressed in the existing vocabulary. If not, the vocabulary must be expanded accordingly.
Rules can also be modeled, with the business user taking the part of mapping their business logic and IT being responsible for integration of data as well as integration of the generated code into the target application. Business rules are also key to the
Enterprise Decision Managementapproach to decision automation.
Increasingly, business rules are also viewed as a critical component of
Business Process Managementsolutions, due to the need to ensure flexibility.
Relation to database management
As argued by
Christopher J DATE, business rules translate into data integrity constraints when one thinks in terms of the relational model of database management. Thus, a truly RDBMScould be thought in terms of a declarative business rules enginewith added data managementcapability. This is currently implemented in Rel and Alphora Dataphor.
However, business rules need not only be regarded as constraints. They can also be used to specify constructive business policies, such as "preferred clients get a discount of 10%". Used in this way, business rules are like SQL queries, rather than data integrity constraints. This solution direction is implemented in USoft by Ness.
Relation to Business Process Management
Some analysts believe the combination of business rules technology with
Business Process Managementoffers an agile approach to workflow and enterprise integration. BPM and BR software support business goals by managing and running business processes and business rules in separate yet complementary ways. A business process is often a complex map of flow controls. It might have many subprocesses, decisions and while loops. Wherever a decision or while loop appears, business rules can evaluate the data provided by the process and control the basis for change in flows.
Often there are separate reasons for updates to processes or rules. New regulations or business strategies may affect the rules without changing core business processes. New applications or procedures might change the business process. In either case, a composite approach to rules and processes can be very flexible.
As more and more BPM vendors either add business rules engines to their BPM engines or OEM business rules management systems, business rules seems to be becoming a subset of BPM.
Business Rules Engine Providers
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