Reviews

The following reviews have been submitted to Amazon:

Hugely accessible guide to decision modelling with DMN from one of the field’s highest regarded experts

by Nick Broom

If the two main releases about DMN this year from Bruce Silver, and James Taylor/Jan Purchase were the equivalent of the summer blockbusters, DMN in action with OpenRules by Dr Jacob Feldman is the independent film clearing up at Cannes.

This book is built around real-world examples and takes the reader straight into modelling practicalities, building up the complexity of the examples with each chapter. It does assert a level of prior knowledge, essentially, “you’re already familiar with the ideas and you want to know how to actually do it”. So it eschews the various scene setting and levelling you’ll find elsewhere in favour of getting your hands dirty.

It’s delivered through a novel narrative between the reader and the author, which immediately makes it very accessible (again, assuming you’ve got some of the prior knowledge). The great thing about OpenRules is that its interface is Excel, which means that, even without OpenRules itself, the reader can start creating decision tables straight away in a tool that most people will have, which ultimately is the quickest way to get to grips with how DMN works.

OpenRules has been around for a long time and has been one of the forerunners in support for decision modelling practices and with it being open source, there’s a lot to recommend it as a tool, not just from a technical perspective but from the point of view that it’s been developed by a team with a real understanding of the practicalities of modelling, not just a slavish adherence to a specification that has seen some tool vendors ignore business expertise in favour of purist technical interpretation and thus deliver something that has limited real-world value.

I’d highly recommend this for business analysts and any business users that work with any form of business rules as the perfect way to understanding how to start decision modelling right now to a specification that is on a dramatic rise to becoming the standard for defining logic.

Fast, Direct and Hands-On Introduction to Decision Modelling Using OpenRules

by Jan Purchase

Prominent and prolific contributor to the field of decision management, Jacob Feldman, has written a guide to decision modelling that is approachable, focused, intensely practical and engaging. An ideal read for the newcomer who wants to start building models quickly.

Jacob’s book quickly gets to the point. Assuming the reader is already aware of the motivation, aims and benefits of decision modelling, the book launches straight into the practicalities of building the reader’s first OpenRules decision model by page 14 and completes it twenty pages later. Despite this swift pace and directness, the text is written in a light, easy-to-read style using a stylized conversation between the author and a reader. It is split into seven dialogues, each featuring hands-on, OpenRules exercises of increasing complexity from a variety of business domains. Each dialogue has clear goals and is designed be completed in one sitting. The book uses the exercises to explore the core ideas of the Decision Model and Notation (DMN), a decision modelling standard defined by the Object Management Group that is becoming an increasingly important means of expressing business logic. At 149 pages in total, the entire book can be read in a day or two.

The book uses a step-by-step approach to expressing business logic, using authentically worded requirements, that arms the attentive reader with the pragmatic essentials of decision modelling. It also tackles a few more challenging techniques, on the edge of the current definition of the DMN standard, such as iteration. Much of the material can be understood by readers with no technical experience (‘non-programmers’), although some sections feature Java snippets, data types and response objects which will be unfamiliar to some business analysts. Although OpenRules is based on the Decision Model and Notation (DMN) there are many key differences between them. As models are developed in the book, the author explains some of these differences.

The practically of the book is enhanced by the fact that all the featured exercises and the OpenRules software can be downloaded—encouraging readers to get some valuable, hands-on experience of decision modelling by experimentation. I was very pleased that the book promotes a test-driven approach to decision modelling and quickly illustrates the importance of establishing a glossary and a set of test cases to underpin decision models. The book’s website companion also allows the behavior of the models to be analysed—a real boon to learning.

The brevity, easy-going style and practical approach of the book make it a very effective means of learning the foundations of decision modelling with OpenRules in a very short time.

If you want to learn how to apply DMN in real life scenarios this is a book for you

by Zbigniew Misiak

The book consists of dialogues which will guide you through the most useful DMN elements. For each dialogue there are also possibilities to test this knowledge in practice with OpenRules.
The book does not cover each and every element of the specification, but instead shows you the ones you need to know and gives you valuable background info about the standard.
Practical examples start from easy ones and move to more complex so that at the end you can handle real life scenarios.
Great guide from a DMN acclaimed expert!

Intuitive learning without unnecessary information overload

by Erik Marutian

First, I have to say that I’ve used OpenRules in production systems and have already found it to be very intuitive – and that was before this book was out. Now that the book is out and having gone through most of the book already, can only say that the overall learning curve has been simplified even further – the choice of how the material is presented is really well suited for “just in time”, intuitive learning without unnecessary information overload. This allows anybody to quickly learn and become productive with rules engines based solutions in general and OpenRules specifically. For the latter, the book provides all the information necessary to package your OpenRules based solution as a ready to go, deployable solution.

A homerun by Jacob Feldman

by Alexander Yudin

I really like the way this guide explains how to build executable business decision models for someone who is not a programmer. It shows how to use Excel to define business rules and nothing is hidden – you are able to read the book and also open the Excel files to see all the implementation details. And I like the presentation style – a fictional reader represents a real reader and has the author address questions that come up. After going through the first three dialog-sessions you will be ready to build your own decision models. I believe it is important for a business analyst to not only define the business logic but also be able to create test cases to check that the logic is correct. I am now in the process of downloading the OpenRules software and I like the fact that everything is open sourced!