Download the workshop slides.

1. Basic Handyman example in DMN

1.1 Assignment

We use the BPMN.io DMN modeller to represent the following decision procedure:

• First, you need to know if you can make a hole in the wall:
  • You can do this in brick or wood, but not in tile.
• Then, you decide how to hang the object:
  • If you can make a hole and the object weighs <= 20kg, use nails.
  • If you can make a hole and the object weighs > 20kg and <= 40kg, use screws.
  • If you can’t make a hole and the object weighs <= 15kg, use glue.

Steps:

• Download the boilerplate model and open it in the modeller
• Open the decision tables by clicking on the green squares and fill in the correct information.

1.2 Solution

Solution file

1.3 Handyman DMN in Interactive Consultant

You can see the same DMN model in the Interactive Consultant by clicking on “Interactive Consultant” at the top.

2. Handyman example in cDMN

2.1 Assignment

Starting from this partial model, represent the following constraints using cDMN constraint tables:

• Nails support weights up to 20kg, screws up to 40kg and glue up to 15kg.
• Nails and screws require a hole in the wall, which is possible for brick or wooden walls, but not for tiles.

2.2 Solution

View the complete solution here.

3. Updating the Handyman example: diamond drill bit

3.1 Assignment

Extend the model to allow holes to be drilled in tile walls if you own a diamond drill bit. Starting from the solution of the previous exercise, you will need to:

• Add an additional Bool to represent whether we own such a diamond drill bit.
• Add an appropriate new column to one of the existing tables.

3.2 Solution

View the complete solution here.

4. Component Design

4.1 Basic Model

Starting from this glossary, add the following constraints:

• For the Outer component:
  • If its material is P1, then the max temperature <= 100
  • If its material is P2, then the max temperature <= 150
  • If its material is P3, then the max temperature <= 200
• Same for the Inner component
• The materials for the Inner and Outer components should be compatible:
  • P1 is compatible with P1 and P2
  • P2 is compatible with P1 and P1
  • P3 is compatible with P3

(solution)

4.2 With melting point

We now make the model more readable by adding the information that the “magic numbers” 100, 150, 200 are actually the melting points of the three materials. Starting from the solution of the previous exercise, update the glossary to represent this and then change the constraint table.

(solution)

The resulting constraint table can also be mode more compact with a quantification

4.3 With compatible materials

Similarly to how we added the melting point function, we can also add and define an explicit relation stating that two materials are compatible. This results in this model with named quantification.

How can we now use this to replace the constraint table we had previously?

(solution)

5. Team Selection for R&D Project

For a new research project surrounding “smart compressors”, we want to form a team of capable employees based on some requirements. We are given five employees: Edsger, Ada, Donald, Grace, and Brian. For each of them, we know the following information:

• Focus: Compressor, IoT, and Prototype
• Skills: Project Management, Functional Analysis, Design
• Experience: between 0 and 30 years

The rules for the team are as follows:

• Each member should have a focus on compressors
• Each member should have at least two years of experience
• One of the selected employees will be the Project Lead. The lead requires the “Project Management” skill and at least 5 years of experience.
• At least one of the selected employees should have the “Prototype” skill.

5.1 Team size

We start from the following model, which already calculates our team size. You can already experiment with it in the Interactive Consultant.

5.2 Focus

Update the glossary of the model with the following concepts:

• We have three focuses: Compressor, IoT, Prototype
• Each employee can have multiple focuses

Next, add the focus information to the model.

solution

Now, add a constraint that all selected team members should know about compressors.

solution

5.3 Years of experience

Update the glossary with the following concepts:

• Years of experience can range between 0 to 30 years.
• Each employee has exactly one value for years of experience

Next, add the experience information to the model.

solution

Now, add a constraint that all selected team members should have at least two years of experience.

solution

5.4 Project lead

Update the glossary to represent that the team should have a project lead.

Add the constraint that the project lead must be selected, and have at least 5 years of experience.

solution

5.5 Skills

Update the glossary with the following concepts:

• There three different skills: Project Management, Functional Analysis, Design
• Each employee can have multiple skills.

Next, add the skill information to the model.

solution

Extend the previous constraint to say that the project lead should have the Project Management skill.

solution

5.6 Design constraint

One member of the team will be the designer. This cannot be the same person as the project lead.

• Add a designer role.
• Express that they may not be project lead, and should know how to design.

solution

Test this out in the IC. Does this produce the desired result? If not, what goes wrong?

Try to fix the model to get to the complete solution.

solution

Useful links

• Workshop slides.
• cDMN documentation
• cDMN editor
• Information about IDP-Z3 engine