What should happen when a business rule is broken? As discussed in this post, Business Analysts should answer three questions:
Developing a friendly, secure business solution requires overt answers to these questions for at least a subset of business rules. (As explained later, defaults can be assumed for the others.) It should also be possible to easily change or evolve the answers (including defaults) after deployment of the business rules, thus permitting the business capability to become incrementally smarter.
The goal is context-dependent, pinpoint reaction to breaches in real-time. Addressing breaches intelligently is key to creating friendly, agile, secure business solutions, ones that can evolve rapidly in day-to-day operation.
Breach Question 1. Enforcement Level
How strictly should a behavioral rule be enforced?
- How strictly should the business rule be enforced?
- What message is appropriate?
- What response is needed?
Business Rule: A service representative must not be assigned to good customers in more than 3 states or provinces.
Ask: How strictly should this business rule be enforced?
Enforcement Level: Override by pre-authorized actor
Table 1 lists the most common enforcement levels for behavioral rules.
Common Enforcement Levels for Behavioral Rules
||Violations are disallowed in all cases – achieving some newstate successfully is always prevented.
|override by pre-authorized actor
||The behavioral rule is enforced, but an actor with proper before-the-fact authorization may override it.
|override with explanation
||The behavioral rule may be overridden simply by providing an explanation.
||Suggested, but not enforced.
Be sure not to overlook the last enforcement level Table 1. A business rule that is actively evaluated, but not enforced, is (literally) a guideline. Guidelines are business rules too!
Breach Question 2. Guidance Message
What message should be returned when a breach of a business rule occurs?
When a business rule is breached, somebody, often a business actor directly engaged in a business process, needs to know about it. The breach means the work being conducted has strayed outside the boundaries of what the business deems acceptable or desirable. From a business perspective an error has been made, so some error message should go out. What should that error message say?
As a default, we like to say that the business rule statement is the error message. From a business point of view, that equivalence must always be true – what else are business rules about?! Rather than saying ‘error message’ (which sounds technical) or ‘violation message’ (which sounds harsh, especially for guidelines), we say guidance message.
Generally, guidance messages should be as friendly and as helpful as possible. For example, guidance messages can be written in a more personal, informative style. More explanation or suggestions can be appended or substituted as desired. Perhaps a link to other media (e.g., a how-to video) can be provided. Sometimes the best guidance message takes the form of some icon or signal (e.g., a warning light turning to yellow or red).
Guidance messages frequently need to be specific to the circumstances in which a breach occurs (e.g., what role or user produced it). In all cases, guidance messages should be made available only to people who are qualified and capable.
Breach Question 3. Breach Response
Does the breach response for a business rule need to be more selective, rigorous, or comprehensive than simply a message?
Business Rule: A cursory review of a received engineering design must be conducted within 5 business days of the date received.
Ask: What breach response is appropriate for this business rule?
Breach Response: The received engineering design must be brought to the attention of the manager of the department by the morning of the next business day.
Breach responses can take any of the following forms:
Multiple breach responses might be desirable for a business rule. They might also need to be specific to the circumstances in which a breach occurs (e.g., what particular part of a process is being performed). Usually, breach responses serve to increase user-friendliness. In cases of potential fraud or malicious business behavior, however, breach responses should be much more aggressive.
Natural defaults for the three breach questions are listed in Table 2.
- business rule (as illustrated above), or set of business rules
- processes or procedures
- sanctions or penalties
- operational business decisions
- special notifications, displays or instructions
Defaults for the Breach Questions
||the business rule statement itself
Fundamental to business analysis with business rules is the assumption that breaches of business rules can be detected. If you can’t detect breaches, how can you run the business?! To say it differently, if you can’t detect breaches of a business rule, but you can still run the business, perhaps you don’t need the business rule at all(!).
This breach question applies only to behavioral rules. Since definitional rules must always be true, they are in essence strictly enforced.
Table 12-1 of Business Rule Concepts, 3rd Ed. (Chapter 12) discusses additional enforcement levels. It also provides tips for designing procedures with business rules.