## 1 Introduction  
Business process models are intended to be bridges between technical and business people. They are used to describe sequential, parallel, as well as alternative workflows within an organization, which aim to achieve the required goals. Visualizations of processes make them much easier to comprehend than textual descriptions. Therefore, associations such as the Object Management Group (see: [[http://www.omg.org/](http://www.omg.org/)]([http://www.omg.org/](http://www.omg.org/))) make an effort to create universal and comprehensive standards for the visual design of process, decision and software models [1; 2; 3]. A properly-designed model does not require major enhancements as long as there are no significant changes in the process. However, as requirements for modern software systems, as well as organizational structures in companies are constantly changing, there is a general need to redesign processes frequently. Thus, it is crucial to use an efficient modeling approach.  
Because processes are often modeled manually by designers, the time spent on process acquisition can be shortened when prototypes of the models are generated. The aim of this work is to simplify the business process modeling phase by significantly limiting the number of iterations between the designer of the process and its participants. Our method tends to automate the modeling process by merging data provided by multiple process participants into a semi-structured form, as well as describing algorithms that transform this specification into a visual form.  
The approach presented in this paper is related to various research areas such as business process modeling, process planning, as well as constraint programming. Figure 1 presents an overview of the proposed method. It describes the sequence in which data collected from different process participants are merged to generate a BPMN diagram. This paper introduces the approach, describes briefly its two first phases and is focused on the third and fourth phase of the approach, i.e., BPMN model generation.  
In the first phase, all the process participants are given a spreadsheet-based form to insert information about executed tasks, along with the conditions and effects of their execution. Then, the files are merged into one specification where the consistency and uniformity of task names, as well as used data entities should be assured. In the next step, the specification is formalized as a Constraint Satisfaction Problem (CSP) and is passed to a constraint solver in order to generate a synthetic workflow log (or simply log) of the process. Such a log, which is a set of all admissible execution sequences, is then used to generate a final model by one of two different methods, namely process mining (Phase IVa) and graph-based model composition (Phase IVb).  
This paper is organized as follows: In Section 2, we provide an overview of business process modeling along with a brief specification of BPMN, which is the notation used in our approach. In Section 3, we present related works in the area of process planning and transforming declarative models into an imperative form. The concept of gathering process data to form its declarative specification is presented in Section 4. Section 5 describes the constraint-based model, which is used to generate a set of synthetic traces of the analyzed process, while in Section 6, we present two ways of composing a BPMN diagram based on the generated log. The detailed specification of our approach was evaluated in Section 7 in terms of its ability to support complex process flows, as well as different BPMN constructs. Our idea is summarized in concluding remarks presented in Section 8.  
Figure 1: Outline of the approach divided into four main phases.