These are the slides of my talk at Code Generation 2010. I share my experiences during the development of a Model-Driven Software Factory. This factory is based on multiple Domain-Specific Languages (DSLs), together describing a Service-Oriented Business Application. All DSLs have a graphical concrete syntax and are aimed at involving domain experts in the software development process. The factory has been used for many projects in the last five years and its user base is growing fast.

1. Lessons learned in building a
Model-Driven Software Factory
Johan den Haan
Head R&D Mendix
@JohanDenHaan

2. IT costs a lot, but is not fast
enough to meet Business Agility
wishes

3. We are going to
fix it today!

4. Join me on my
journey

5. Viewpoints
Context
A basic Model-Driven Software Factory
Releasing the product
Growing a user base

7. What kind of business problems do
we want to solve?

8. Application characteristics
 Time-2-market
 Flexible
 Integration with commodity applications
 Portal / Rich user interface
 Domain knowledge

9. Who is our
target user?

10. Lessons learned
 Product dev. starts with a customer need
 MDD asks for repetition
 First step in building a MDSF is domain
definition
 Make a clear choice about your target user
 Define the most important domain concepts
 Think about a methodology early - it will
influence your DSL design and tool

12. Browser
Styling & user interaction
CSS, HTML, JavaScript
Client-side logic
Server communication
JVM
Java
Flows & actions API & connectors
Access rules
ORM
Database
SQL
Data

13. Browser
Styling & user interaction CSS
Client-side logic
Rich Forms DSL
Server communication
JVM
Microflow DSL
Flows & actions API & connectors Mapping DSL
Access rules Security DSL
ORM Domain model
Database
Data

14. How to support our target users?
 Model should be easy to
– Read
– Browse
– Search
– Keep consistent
 Deployment
– Should be easy / non-technical
– Model execution / interpretation
– Cloud infrastructure

16. Lessons learned (1)
 Interpretation is a viable alternative for code
generation
 Use model checks to prevent errors early
 Make sure you can navigate and search
 Make DSLs as declarative as possible
 Prevent property explosion
 Create flexibility for unforeseen uses

17. Lessons learned (2)
 Do not only focus on development phase
 Deployment can be slow – compliance with
code style, architecture, server config, etc.
 Cloud infrastructure can automate
deployment
 Grow your factory bottom-up
 Always look at existing standards first

19. Applications build with
our product will suffer
from a double release
cycle

20. We need an
extension mechanism

24. How to ensure
quality?

25. Lessons learned (1)
 Put effort in documentation, training, and
templates
 Create flexibility to prevent double release
cycle troubles
 Release management is much easier with a
plugin infrastructure
 Be always backwards compatible

26. Lessons learned (2)
 Deprecate model structures and provide
alternatives for breaking changes
 Create (semi-)automated tests using test
models
 Learn from reported bugs
 Do not only test the technical implementation

28. Why should he
use our product?

29. We should focus on
partners, but do
some lighthouse
projects ourselves

30. Make it easy to start

31. How to create an active user base?

32. Lessons learned (1)
 Make it compelling for partners to use your
product – what’s in it for them?
 Start doing lighthouse projects yourself
 Sell business solutions to business people
 Eat your own dog food
 Integrate ‘community tools’ in modeling
environment

33. Lessons learned (2)
 Use a reputation system for your support
forum
 Give partners incentives to build reputation
 Create a place to download an share
templates, extensions, etc.
 Make it compelling for partners to publish
content

34. Viewpoints
Context
A basic Model-Driven Software Factory
Releasing the product
Growing a user base

36. Lessons learned in building a
Model-Driven Software Factory
Learn more: world.mendix.com
Read more: www.theenterprisearchitect.eu
Connect: @JohanDenHaan