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Dr. Konrad Wieland

Dr. Konrad Wieland

Dr. Konrad Wieland

LieberLieber Software GmbH (Consultant)
Dr. Konrad Wieland is an expert in modeling and model-based software development in the most diverse domains. Even during his dissertation at the Vienna University of Technology, he published a host of articles on team-based modeling and software configuration management. Since 2012, as Consultant and Product Manager at LieberLieber he has continued to expand his expertise in these and other areas in and around Enterprise Architect.

The rapidly-growing automotive supplier Preh Car Connect GmbH is re-establishing its software development on the Product Family Engineering methodology. Preh engineers, already longtime Enterprise Architect users, were recently introduced to LemonTree from LieberLieber. The new concept was unveiled in a joint presentation and is nothing short of ambitious.

Vienna/Dresden – Product Family Engineering (PFE) helps companies more easily reuse or issue new versions of software they have already created. The resulting variants differ in their functional scope, but the basic components of the software are used again and again. Computer scientist Tim Michaelis, software architect at Preh Car Connect: “As our company continues to see strong growth and the implementation of numerous series projects, we can effectively use components of our own software again and again. So far, however, this has only been possible through the laborious manual copying of software architecture models. Together with LieberLieber, we are now working on a project that will automate such processes. LemonTree is an important building block for us in order to be able to implement these development steps faster and more easily.” At Preh Car Connect, a total of approx. 1,200 employees work at eight locations worldwide. The headquarters and central development site of the company is located in Dresden. For more than 20 years, the company has been developing and producing high-quality infotainment systems for well-known OEMs such as the Volkswagen Group.

Presentation at TdSE 2017
LieberLieber CTO Roman Bretz and Tim Michaelis presented the new concept at the “Tag des Systems Engineering 2017” conference (TdSE 2017, engl.: “Systems Engineering Day 2017”), held from November 8-10 in Paderborn, Germany. The presentation, entitled “Model Versioning in Product Family Engineering with Enterprise Architect and LemonTree,” highlighted how cost and innovation pressures are the key drivers for the changeover to a PFE approach. Roman Bretz: “At the TdSE 2017 conference we introduced our concept for distributed work on various model versions while always keeping the ’basis software platform’ consistent. The main idea behind it is the application of already-existing approaches that are well established in the area of source code configuration management.” The growing necessity to tighten development cycles requires close cooperation of all customer project and platform development stakeholders. The situation wherein complex products made up of many components are managed by special teams that previously worked on a common model has brought forth completely new challenges at the model level. To establish the so-called “basis software”, which forms the core of the individual product lines, as an independent platform and to adapt and expand it into in individual customer projects is not possible within the standard functionality of today’s modeling tools.

Grafik 2

Taking steps toward Product Family Engineering
A study published in 2017 by the German management consultancy Unity AG (see box) describes various stages of expansion in PFE. Although there is a clear move away from integration to anticipation in software engineering, in a practical sense this reorientation is still in its infancy. Michaelis: “PFE represents a big change to us in the company, to which the support provided by tools such as LemonTree is important. It helps us to more precisely track changes in the project models.” The introduction of this new method places Preh squarely among the pioneers in the automotive industry, achieved with the help of LieberLieber experts. Bretz: “We are proud to bring our know-how into this project. It’s a perfect fit with our company philosophy, which is to apply only state-of-the-art methods in practical model-based software and systems engineering scenarios.” As verified by the aforementioned study (p. 22), in this field there is certainly still enough to do: “In digital transformation, model-based systems engineering is the basis for mastering the complexity of vehicle development. The model-based approach promotes standardization. Distributed development, variant management and cross-domain mechatronic development processes are becoming more effective and efficient.”

Study: Automotive industry in transition
In its study entitled “The Digitization of Product Creation – The Automotive Industry in Transition,” Unity AG sheds light on the digitization of product development in the automotive industry: “To summarize, all these challenges point to two aspects: complex, networked contexts and high rates of change. Both will not be manageable with current development methods. Instead, it is important to establish new and consistent model-based processes on a cross-disciplinary system engineering foundation.” (p. 12). In regards to model-based PFE, the article states: “Model-Based Product Family Engineering promises to escape this dilemma. Overriding goals are the control of the variance and the shortening of the time to market. At the same time, improvements in individual components are to be reflected in many different products… In addition, the model-based approach ensures both the consistency of development work and the singularity of the development effort.” (p. 23)

Schulze, S.-O./ Steffen, D./ Wibbing, P./ Wigger, T.: OPPORTUNITY: Die Digitalisierung der Produktentstehung – Die Automobilindustrie im Umbruch, UNITY, 2017

Grafik 1

More: https://www.lieberlieber.com/



Hello fellow Enterprise Architect user!


we are very happy that the new release of EA's diff & merge extension LemonTree (c) by LieberLieber is available.

You can request the new version 1.3: http://lemontree.lieberlieber.com

Benefit of all features of your version control system by checking in EAP files! But do you already know that LemonTree can also diff DBMS such as SQL Server, Oracle, MySQl, etc.?



************* Release notes *************

We regularly provide updates like this to improve LemonTree.

Especially this release 1.3 brings improvements in speed and stability.

In addition, we have implemented the following improvements:

-          Dependencies of changes: When the user is manually changing the merge result, heavy dependencies of changes are now considered.

-          The order of swim lanes are now correct after merge.

-          SVN integration is now more robust: The SVN hooks are not used anymore

-          Git Integration: Bug fixed when writing model

-          Problems with ports and their types (classifier + redefined port) are solved.

-          Better logging

-          Additional UI fixes



Monday, 06 March 2017 08:12

Fresh News: Enterprise Architect and Git

It started off over 24+ months ago... there was a product we were building that created a solution to a problem called LemonTree (c).

Now if you haven't heard of it, it's a tool to help alleviate a common challenge that many EA modelers face: Branching and merging Enterprise Architect projects (models).

Fast forward
18 months later, after huge success of LemonTree, we started to recognize the next challenge, support of other popular version-control systems - more particularly Git.

And that's when LemonTree with Git integration was born.

Today, we are EXCITED to announce
theofficial major release of LemonTree with Git support to the public.

You cansee it in action, how it works here!

Here's LemonTree at a glance:

  • Uses fine-grained 3-way diffing algorithm.
  • Enables the development of multiple parallel branches of models to target and merge individual models.
  • Acts like an external diff/merge program (EA independent).
  • Seamlessly integrated into TortoiseSVN and Git.
  • Shares the benefits of Version Control repository.
  • And much more..

Go check our latest release v1.2: LemonTree here..

We have often to do with EA models we’ve never seen before. In such cases, you have either to click through the project tree (can be confusing and time-robbing) or you use some pre-defined Model Views.

The picture bellow shows how it could look like on your machine when you’ve read the article to the end.

Model Views - Diagrams

The feature could be very helpful also in other situations and we wonder why it’s used so rarely. Using Model Views you can create access points to any elements you want independently from its position in the project browser. It can be compared with database views if you are familiar with databases.

The only thing which is a bit annoying while creating a view, you have to create a model search first. If you use the Query Builder, the created search can be used as a basis for a view without any problems. In case the functionality of the Query Builder is insufficient and you need to create an SQL query, it has to fulfill some criteria. Within your query, you need to define three fields: CLASSGUID, CLASSTABLE and CLASSTYPE, as shown in the following example:

SELECT ea_guid AS CLASSGUID, 't_diagram' as CLASSTABLE, Diagram_Type AS CLASSTYPE, Name, [Version], Author, Stereotype, CreatedDate, Diagram_Type, ModifiedDate
FROM t_diagram
WHERE t_diagram.Diagram_Type = 'Statechart'
ORDER BY ModifiedDate ASC

Diagram Views help a lot to explore unknown projects. Thus, we have created views for all common diagram types.

Feel free to download and to use them: Searches and Views

First step – open Model Search / Find in Project dialog and import the xml file that contains the definition of searches:

Model Views - Import Searches


Second step – activate Model Views window and import the xml file that contains the definition of views:

Model Views - Import Views


Thursday, 03 November 2016 14:18

New SysML Book for Enterprise Architect Users

We are very proud to announce that Dr. Oliver Alt from LieberLieber has finished a much enhanced version of his previously german SysML book in english.

“Practical Model-based Systems Engineering with SysML – Handbook”



- Model-based Systems Engineering with SysML and the Control Chain approach
- All in-practice-relevant topics for Model-based Systems Engineering are covered in this book
- Learn about SysML and the related state-of-the-art technologies and how to use them with Enterprise Architect

This book is your key to learning all of the relevant things you need to know about the practical use of Systems Modeling Language (SysML) and Systems Engineering for mechatronic systems.
It introduces you to the Control Chain approach for describing hardware/software systems on a logical level.
With this methodology you can describe hardware and software components as a comprehensive functional assembly.
This book is also your introduction to Systems Engineering and SysML as a pragmatic approach.
Only relevant modeling language elements used in everyday practice are covered to keep it as simple as possible, and to reduce learning effort.
In spite of this, you are provided with enough background information for your daily work in Systems Engineering for designing simple or even very complex systems.

New state-of-the-art topics have been added, such as data integration with ReqIF, system data linking using OSLC-technology, Industry 4.0 and Big Data in Systems Engineering.

You can buy get your copy on Amazon (click this)!

Or buy it here via share-it (click this)!


Software and Systems Engineering, as any other interdisciplinary activity, requires the ability and means to build systems which are so large and complex that they have to be built by teams or even by teams of teams of engineers. In combination with a model-based approach, these teams need the possibility for modeling in a concurrent way. With other words, multiple users must be able to work on the same model in parallel or even on multiple versions of the same system. In code-centric software engineering, developers profit for years from the features provided by Version Control Systems (VCS), whereby one of the most important features is the possibility of comparing and merging changes of the same file. The key technique hereby is the so called three-way difference analysis which is also considering the common ancestor version of the artefact under comparison. Traditional approaches uses text- and line-based comparison tools, which are not suitable for graphical-based models.

In general, two different versioning strategies exist to cope with the concurrent evolution of one artifact. These are described in the following:


When pessimistic versioning is applied like it is implemented in EA, an artifact is locked while it is changed by one developer. Since other developers cannot perform any changes while the artifact is locked, conflicts are completely avoided with this strategy. However, the drawbacks are possible idle times for developers waiting for the release of a locked artifact.

To avoid such idle times, optimistic versioning allows the developers to change the same artifact in parallel and independently of each other. This process is depicted in the following figure:


The following videos give you insights into the latest developments in model versioning and act as tutorials in how you can set Enterprise Architect models under optimistic version control:

Tutorial 1 – LemonTree Introduction to Model Versioning


Tutorial 2 – LemonTree Model Comparison Tutorial


Tutorial 3 – LemonTree Concurrent Modeling Tutorial

For more information please visit: lemontree.lieberlieber.com

Tuesday, 20 September 2016 10:30

Fresh Modeling Versioning with LemonTree

LieberLieber is proud to present a brand new Enterprise Architect tool named LemonTree (c). The most important function of this ground-breaking product is the diffing and merging of model versions.

Now, you do not have to lock your packages. Just check-in your eap files in your version control system!

Standard approaches use line- and text-based applications that do not suffice for graphic models. Only the finely-grained 3-way diffing algorithm that considers the model’s graph structure enables an exact comparison between two models.