Tim Bass
11-11-2008 02:18 PM
In
GPS, GeoLogging and CEP I was really impressed with the movement toward multisensor data fusion and situation detection as commented by Alex and Marco.** Both Alex and Marco realize that basic track-and-trace tends to be a supporting role in many CEP applications; and that one core functionality that “graduates” an application to a “CEP application” is the degree of complexity in the object-object situation refinement.* (Note:* there are some classes of tracking that are quite complex, for example Kalman Filters).
It appears to me that both Alex and Marco tend to agree that simple rule processing, an important subclass of event processing, does not necessarily automatically “graduate” an application to the status of “complex event processing.”* However, as numerous readers have pointed out, processing rules can be quite complex.* So, this leads us to the obvious question:
What Defines Complexity in Rule Processing?
I have been thinking about this question, and do not have a good answer.** For example, I don’t think we can define “complex” as processing a simple rule or rule-based algorithm against high volumes of events (in a stream).* This is not complex,
per se.* (Software vendors tried this early on and it went over like a lead balloon!)
So, what exactly would be the various parameters we could use to define, precisely, what is complexity in rule processing?
For example, in
On rule complexity: A structural approach Dietz says:
This paper first examines existing accounts of rule complexity and presents a conceptual analysis of the term ‘rule'. It then proposes that ‘complex' should not be equated with ‘difficult', but used in a purely structural sense. Specifically a conditional formulation is proposed in which the number of concepts in the antecedent and the consequent, the number of subconditions, and the number of ‘if-then' connections (subrules) within a given rule domain govern complexity.
In another example paper,
Complexity Measures for Rule-Based Programs, O’Neal and Edwards said:
Software complexity measures are quantitative estimates of the amount of effort required by a programmer to comprehend a piece of code. Many measures have been designed for standard procedural languages, but little work has been done to apply software complexity concepts to nontraditional programming paradigms. This paper presents a collection of software complexity measures that were specifically designed to quantify the conceptual complexity of rule-based programs. These measures are divided into two classes: bulk measures, which estimate complexity by examining aspects of program size, and rule measures, which gauge complexity based on the ways in which program rules interact with data and other rules. A pilot study was conducted to assess the effectiveness of these measures. Several measures were found to correlate well with the study participants’ ratings of program difficulty and the time required by them to answer questions that required comprehension of program elements. The physical order of program rules was also shown to affect comprehension. The authors conclude that the development of software complexity measures for particular programming paradigms may lead to better tools for managing program development and predicting maintenance effort in nontraditional programming environments.
A quick survey of various authors on the topic of rules and complexity yields a number of interesting papers, but I did not come up with anything (yet) that would directly answer the question at hand,*
What Defines Complexity in Rule Processing?
Please post your thoughts and references.
Source...
