The rules for corporations derive from two sources. These are the country's statutes: in the US, usually the Delaware General Corporation Law (DGCL); in the UK, the Companies Act 2006 (CA 2006); in Germany, the Aktiengesetz (AktG) and the Gesetz betreffend die Gesellschaften mit beschränkter Haftung (GmbH-Gesetz, GmbHG). The law will set out which rules are mandatory, and which rules can be derogated from. Examples of important rules which cannot be derogated from would usually include how to fire the board of directors, what duties directors owe to the company or when a company must be dissolved as it approaches bankruptcy. Examples of rules that members of a company would be allowed to change and choose could include, what kind of procedure general meetings should follow, when dividends get paid out, or how many members (beyond a minimum set out in the law) can amend the constitution. Usually, the statute will set out model articles, which the corporation's constitution will be assumed to have if it is silent on a bit of particular procedure.
A business rules engine is a software system that executes one or more business rules in a runtime production environment. The rules might come from legal regulation ("An employee can be fired for any reason or no reason but not for an illegal reason"), company policy ("All customers that spend more than $100 at one time will receive a 10% discount"), or other sources. A business rule system enables these company policies and other operational decisions to be defined, tested, executed and maintained separately from application code .
In planning development of a rule-based application, you first need to determine how rules will fit into your business processes. Your application will create an instance of a policy and supply it with data, or facts, on which to operate. The policy object encapsulates the rule engine and provides a single point of entry through which to run it.