This is not an abstract.
Firstly, why is it addressed to a company? A diploma thesis is an academic paper documenting your work and your findings to the thesis committee. It's not a manual that documents some program for a company. And why is the second sentence (Furthermore, each user...) even in the thesis at all? It's completely unrelated to anything you write or should write in a thesis. If you want to tell them that everyone's got access there's email for that.
Secondly an abstract should answer some questions about a thesis:
What have you done?
I have no idea. You're not writing about the things you did, at all. This is a real problem, because THAT is what your thesis should be about. And since the abstract is supposed to allow a cursory reader an insight into the contents of your thesis this cannot be called an abstract without this.
Why was it done?
You're stating a problem but you're not telling why this is a problem. Instead you go into a lengthy description of some obscure project managment process that's not even required to know to understand the abstract. I'm not even sure that this whole thing is required to understand the thesis, because process and requirements for a solution are often two very different things.
How was it done?
Again, you ommit this completely. While not as important as the What? this, too, is part of the flesh of your thesis and should be present.
What are the key results?
You're scratching the surface of this in your second to last sentence, but is that all? How does that warrent a diploma thesis that seems to have been written by more than one person ("Our diploma thesis...")? If there's more to it, tell the reader.
Why is it important?
One could argue that your last sentence answers that question. However, if I start at what you state to be the problem (team members cannot track tasks) I fail to see how that relates to digital negotiations.
I would suggest you delete this and write a new abstract from scratch. Answer the questions, separately. Then write an abstract based on these answers by bringing them into a logical order that the reader can follow easily. Remove everything that's not directly necessary to understand the abstract (for everything else you still have the introduction part of your thesis).
Our diploma thesis is primarily addressed to the e1 Business Solutions GmbH. Furthermore , each user receives8 global access to the automated project management system.
The problem is that the project team does not know which tasks have to be done for a certain deadline and what the tasks are about. A positive program execution is achieved1 when the project lead2 sends a project proposal to the specialist who checks it for correctness and finally approves it.
Afterwards, the portfolio manager analyses the appropriate budget allocation3 among all projects and therefore triggers the release. The project manager finalises4 under inclusion of the principal a project order. At that point5, employees are allocated to the project and the project is started6. If any project changes should be necessary during the8 implementation, they can be negotiated with the principal.
Lastly, the project manager completes the project and hands it over to the principal, who accepts the work.
Now, the project team can see all the tasks in the project-view and what is going on. Our efficient9 workflow management system mainly helps the e1 Business Solutions GmbH in doing digital negotiations between the stakeholders as quickly as possible.
1 - I don't really understand what you mean by that.
2 - In my experience in projects we always used "project lead" as a kind of title for people who report to a project manager. But "project leader" is often used to mean a person who actually leads the team even if they're not officially in a lead position.
3 - Also not sure what you're trying to say here.
4 - Finalizes what? There is something missing here.
5 - I'm not acutally sure about that correction. "From then on" doesn't make sense, because the things you describe don't take any time. One could argue that resource allocation is a process, however the process includes making decisions (which you don't mention here) and the action of allocating is, just like starting, instantaneous.
6 - You've done something typically German here, you've used nouns instead of verbs. In English when an action happens you use that action as the verb of the sentence. Even with my changes youre sentence is still not what I would expect in English because it's useing the passive voice. Had I any idea who does the employee assignments and who triggers the project start, I would have included them.
7 - Implementation is the title of a project phase and those don't need articles.
8 - Receives how? Using the simple present for an action means that the action just happens regularly, i.e. for every user that was, is, or ever will be. Is it magic? Or does someone has to do this manually? As said before, describe actions from the point of view of the acting instance.
9 - Is that proven? Do not make claims that you cannot substantiate.
