Overview
In the previous weeks of this course you learned about basic and advanced concepts of business process modeling. This knowledge enables you to model the steps required to achieve a business goal. However, decisions play an equally important role in successfully executing a process.
This chapter covers the basics of decision modeling based on the new DMN (Decision Model and Notation) standard. It introduces how decision requirements are captured and how the decision logic can be defined. Further, it discusses important properties of decision models and possibilities to check their consistency with process models.
Additional to the course material, we also provide you modeling tasks to work on your decision/process modeling skills. For modeling decisions, a modeling tool is very helpful. Here we recommend the Signavio Decision Manager which we explain in detail here.
The lecture comprises seven video clips.
Motivation
It‘s the decisions that make or break your company and there are very convincing arguments why BPMN is not the right language to express them. Rather, the DMN standard is used as a means for separating the concerns of processes and decisions.DMN Overview
Decision models consist of two levels, the decision requirements level and the decision logic level. The former shows how the decision is structured and what data needs to be available to make the decision. The latter specifies the logic to actually make it.Decision Requirements Diagrams
A decision requirements diagram (DRD) is a simple model consisting of few elements. They can be used to specify a decision on a business level by showing which other decisions it depends on and what data it requires. Furthermore, a DRD defines authorities and (legal) documents that dictate the decision logic.Decision Logic
The decision logic is the more technical level of a decision model. There are many possibilities, formal and informal, to describe how to make a decision based on available data. The focus of the DMN standard as well as this course is on decision tables.Semantics of Decision Tables
The DMN defines decision tables as a standard way to represent decision logic. Usually, decision tables consist of a set of rules, specifying which inputs lead to which outputs. DMN decision tables add certain features to that, such as strategies, how to deal with situations in which multiple rules apply for a given set of input values.Analysis of Decision Tables
Given the rules and features of a decision table, one may analyze whether the table fulfills certain properties. For example, one may want to make sure that all possible combinations of input values are actually covered by the table.Consistency of Processes and Decisions
Although DMN can be used without BPMN, associating the two languages has lots of advantages. However, establishing this association is not a trivial task. Therefore, certain criteria must be fulfilled to avoid inconsistencies.
Organization
As usual, there is a number of self tests , to check your understanding of the lectures. You have as much time as required to solve these tests, you can take them at any time and arbitrarily often.
Please recall: At the end of the week, you need to submit a homework . For the homework you should calculate 30-45 minutes and the homework has a time limit (60 minutes) . Please be advised that this test can only be started ONCE (closing the browser does not stop the timer). In addition, the homework starts when you click on the start button on the homework page . So, only click on the button if you are willing to take the assignment. The achieved score in the homework contributes to your total score for this course. You will be informed about your results and a sample solution is published a day after submission deadline.
If questions arise with regard to the lectures, self tests, or assignments, please use the community forum.
Have fun!
Weekly Schedule
Please be aware of the following dates for this week.
- The homework needs to be submitted latest May 23th , 2016, at 22:00 (10:00 pm) CET. Submission is already open; after consulting the lecture material (videos, slides, and reading material), you can start on the homework right away.
- The solution for this week's homework will be published on Tuesday, May 24th , 2016, at 10:00 (am) CET.
- The final exam will be made available on Saturday, May 21th, 2016, at 10:00 (am) CET and needs to be submitted by May 30th, 2016, at 22:00 (10:00 pm) CET
- All times are Central European Summer Time (UTC+2). Please check your local time zone. The remaining time until May 23th, 2016, at 22:00 (10:00 pm) can be checked at the provided link.
Reading Material
- The DMN Version 1.0 specification can be obtained from the Object Management Group. It is the single definition and central reference for questions with respect to the modeling language.
- For a brief overview of BPMN/DMN, you can order a free poster that shows the majority of elements on a single page.
- In 2014, a book on the integration of BPMN and DMN was released. It can be ordered, for instance, at Amazon.
- Decision tables are standardized in DMN. If you are interested in works that led to this important aspect of DMN, have a look at this paper by Jan Vanthienen and Elke Dries.