I have.an use case where I want to use an excel based rule engine. But I can't decide between drools or OpenL. Both seem to have similar features. Both provide a workbench and UI to control rules. Is there any advantage OpenL tablets hold over Drools.
OpenL tablets: https://openl-tablets.org/
Drools: https://www.drools.org/
Related
I am looking for some tool capable of creating complex process of data manipulation which can be more or less easily modified by people who do not write code.
For example, my task is:
fetch data from sourceA
2.1 if data is full - filter it by condition 45
2.2 if data is not full - fetch additional data from source B
if result passes validation - return 1, otherwise 0
This should be described in some readable manner, best option is if one can modify this process in some UI tool.
What are the requirements?
Each process consists of two parts: steps, and a way to arrange them in a sequence.
(1)
The process in each step should be able to
1. emit commands for fetching some data from data-sources and inserting this into process context
2. filter, enrich, transform datasets obtained
Thus each step of this process should be described with some more or less simple DSL.
(2)
The selection of the step to go, i.e. the consequence of steps should be described by some visual tool, or again, as in (1), with some simple dsl.
Can you advise something for this typical, from my point of view, task?
Meanwhile, here are my own ideas.
First think comes to mind is BPMN combined with Drools.
For steps I may use DRL rules: they can make only basic data manipulation themselves, but I can call Java functions from them if I need something complicated.
For steps consequence I may use standart BPMN diagramm.
Mat be, there is something better?
The combination of BPMN with DMN would allow you indeed to describe with these visual standards, the execution of the process and decision logic to be applied, in order to achieve what in the "For example" paragraph.
In order to make it fully accessible by the business people, the BPMN task for fetching the data or performing any interaction with external system, should be prepared in advance and made available during the composition of the BPMN/DMN diagrams.
Alternatively to BPMN+DMN combination, you can look into Fuse or Fuse Online, it cannot describe all the semantics of the BPMN+DMN combination, but with Fuse Online for instance you can fully visually implement the steps you described in the "For example" paragraph.
I am trying to create two independent groups of rules in Drools 6.5 and I can't figure out what's the usecase for the ruleflow-group and agenda-group strategies. They both seem similar.
Reading the documentation ...
2.6.4. RuleFowGroup and AgendaGroups are merged
These two groups have been merged and now RuleFlowGroup's behave the same as AgendaGroups. The get methods have been left, for deprecation reasons, but both return the same underlying data. When jBPM activates a group it now just calls setFocus. RuleFlowGroups and AgendaGroups when used together was a continued source of errors. It also aligns the codebase, towards PHREAK and the multi-core explotation that is planned in the future.
I am trying to come up with a mechanism in ODM to enable or disable a rule based on some input parameters like sales-zone, type of product and 6 or 7 other parameters. I don't want to put all these 7 parameters into the condition within the rule since that would reduce the reusability of the rules.
Are there any features available in ODM that can be used for this? Are there any techniques widely used in the BRMS community for such problems?
You can probably make use of rule selection using IRL at rule task level. Write a function which will determine whether the rule is effective or not for this input param. We are using this strategy. See the below screenshot.
I hope this may help you out. Happy Rule Development. :)
You could extend the extension meta data model and add a property that can be set on the rule to indicate the sales zone associated with the rule. Then on the rule task on the rule flow, use a dynamic select to include or exclude rules that have the property set.
However be aware that with lots of rules, dynamic selects can cause performance issues potentially.
I would like to design a rules based database engine within Oracle for PeopleSoft Time entry application. How do I do this?
A rules-based system needs several key components:
- A set of rules defined as data
- A set of uniform inputs on which to operate
- A rules executor
- Supervisor hierarchy
Write out a series of use-cases - what might someone be trying to accomplish using the system?
Decide on what things your rules can take as inputs, and what as outputs
Describe the rules from your use-cases as a series of data, and thus determine your rule format. Expand 2 as necessary for this.
Create the basic rule executor, and test that it will take the rule data and process it correctly
Extend the above to deal with multiple rules with different priorities
Learn enough rule engine theory and graph theory to understand common rule-based problems - circularity, conflicting rules etc - and how to use (node) graphs to find cases of them
Write a supervisor hierarchy that is capable of managing the ruleset and taking decisions based on the possible problems above. This part is important, because it is your protection against foolishness on the part of the rule creators causing runtime failure of the entire system.
Profit!
Broadly, rules engines are an exercise in managing complexity. If you don't manage it, you can easily end up with rules that cascade from each other causing circular loops, race-conditions and other issues. It's very easy to construct these accidentally: consider an email program which you have told to move mail from folder A to B if it contains the magic word 'beta', and from B to A if it contains the word 'alpha'. An email with both would be shuttled back and forward until something broke, preventing all other rules from being processed.
I have assumed here that you want to learn about the theory and build the engine yourself. alphazero raises the important suggestion of using an existing rules engine library, which is wise - this is the kind of subject that benefits from academic theory.
I haven't tried this myself, but an obvious approach is to use Java procedures in the Oracle database, and use a Java rules engine library in that code.
Try:
http://www.oracle.com/technology/tech/java/jsp/index.html
http://www.oracle.com/technology/tech/java/java_db/pdf/TWP_AppDev_Java_DB_Reduce_your_Costs_and%20_Extend_your_Database_10gR1_1113.PDF
and
http://www.jboss.org/drools/
or
http://www.jessrules.com/
--
Basically you'll need to capture data events (inserts, updates, deletes), map to them to your rulespace's events, and apply rules.
I am looking for tools to aid in the visualization of custom business logic used to perform document generation. The logic is expressed as an object-oriented model consisting of a graph of decision points and rendering actions. The basic building blocks are relatively simple, but the overall decision tree is quite large and complex making it hard to visualize.
We are looking for suggestions on tools and/or graphing libraries that can be used to visually represent the decision tree and rendering actions. The choice of programming language is not critical (Delphi, C#, Java would be great) and we are able to easily extract the logic to XML or other data format as required. The preference is for something that will run under Windows and enable printing or PDF output of portions of the resulting diagram.
Requirements
Decision points can be simple yes/no or multiple outputs e.g. (yes, not, sometimes, always etc).
The decision points are linked to external business logic that exist elsewhere in the runtime environment. We need to label the graph node with the type of decision point (e.g. boolean) and string describing the business rule being used.
Rendering actions are linked to named content objects with optional merge variables and inline rendering logic. At a minimum we need to be able to label nodes with the name of the element and ideally also information about variables used to render the content.
We have considered building something around Visio or WinGraphViz, or perhaps using a third-party graphing/flowchart library. Any ideas or pointers would be greatly appreciated.
After some more digging I found WinGraphViz and DotXML to be the closest match to my requirements. I was previously unaware of the "record" element which allows me to render decisions in the logic flow in a clean and legible manner.
You can consider Morphir with the Elm frontend.
It is a solid tool for business logic modeling, and code generation.
Visualization is coming along as well.