With the recent uptake of Robotic Process Automation in research, also the tooling for building RPA bots comes into focus. So far, the mainly industry-driven domain produced several software programs for creating bots, and with this, diferent non-standardized modeling approaches emerged. Additionally, there are only few unrestricted or even open-source tools available. In this paper, we present Ark Automate, an open-source and web-based platform for creating and running RPA bots. It features interchangeable modeling interfaces, e.g., BPMN, to cater for the diferent user groups and is open for extension by the community.
RPA ecosystem of the Robot Framework3. Furthermore, the software is open source and can be extended, such as for evaluating diferent modeling languages for RPA, implementing robotic process mining approaches, or examining integrations with BPMS.
Ark Automate is designed as a mainly web-based RPA software. Thus, all user interfaces, i.e., for modeling, starting, and supervising bots, are accessible to RPA developers and employees via the browser. The client software, responsible for the actual execution of bots, can be installed either locally or in virtual machines. Before describing the architecture in more detail in Sect. 3, some special features of Ark Automate are briefly introduced in the following.
To a large extent, RPA tools provide a visual modeling interface for creating RPA bots [
Therefore, Ark Automate is designed so that diferent modeling interfaces can be ofered for creating bots4. To ensure collaboration among diferent user groups, the implementation allows users to switch between the diferent layouts at any time, thanks to a model-independent data structure that is used internally and updated in real time.
Currently, BPMN and a Robot code editor are supported, as conducted interviews revealed that BPMN is already widely used to document RPA bots and, moreover, is often already familiar to business users. The code editor, in contrast, is intended for technical users. New interfaces, such as flowcharts, can be added if required, e.g., for experimenting with new modeling methods for RPA.
RPA is used for automating repeatedly executed tasks on computers [
This interface enables business process management systems (BPMS) to launch and monitor RPA bots at the right time in the process, allowing RPA bots to be seamlessly integrated into business processes.
4However, many modeling languages are more powerful than the concepts ofered by Robot Framework and thus need to be constrained. See https://github.com/bptlab/ark_automate/wiki/Documentation-Single-Source-ofTruth for more details.
Ark Automate enables the user and connected systems to closely monitor the current status of running bots in real time. It not only provides information about which operations have already been completed, are currently being processed, or are still to be executed, but it also supplies detailed error messages. This enables new possibilities for an improved exception handling in RPA, e.g., to reveal marginal cases that have not been considered at design time or to enable exception handling at the business process level.
To enable the functionality of diferent interfaces for modeling bots in the front-end, all bots are stored in the same model-independent format in the Robot Repository. In the backend, the Model Interpreter, consisting of parsers for each interface, ensures that models can be translated between the internal representation and the respective modeling languages. General information and metadata about the various operations, i.e., building blocks available for creating a bot, are stored in the RPA Activity Storage.
The Control Interface, connected to the Robot Coordinator in the back-end, provides the functionality to start and configure new bot instances and closely monitor running executions (cf. Sect. 2.3). Additionally, the coordinator exposes an API for managing bot executions (see Sect. 2.2).
Created RPA bots can be executed at any computer having the Local Client installed. After startup, the client establishes a connection to the back-end and awaits new jobs. Whenever the execution of a bot is requested, the back-end retrieves the corresponding bot from the Robot Repository and translates it from the internal data format to the actual Robot Framework code. This code is then transferred to the client software and executed using the Robot Framework. During execution, the client listens for updates from the framework and notifies the coordinator, which stores this information in the Robot Job Storage.
One of the implemented interfaces supports the Business Process Management and Notation standard (BPMN). Figure 2 shows a screenshot of an RPA bot modeled using this interface. Each activity in the process can be assigned an RPA functionality using the sidebar on the right.
In this example, the activity “Enter Current Temperature in Cell” is configured to be a task for automating the Excel.Application. The opened drop-down then shows all operations available for this type of application, and the Write to Cells operation is selected in this case. Subsequently, input fields for configuring the selected operation appear below, here, for specifying the worksheet to modify, the column and row numbers, as well as the value to be entered, which in this case is a variable set by the previous “Get Current Temperature” activity. Each parameter can also be marked to be set at the start of the robot, instead of being hard-coded in the model. While designing the bot, the interface can be switched at any time, e.g., to view the modeled workflow in the actual Robot Framework code that is generated from the model and used for the execution of the bot.
After modeling, the bot can eventually be executed and the progress of execution can be observed live for each task.
Ark Automate is an open-source tool which was developed in collaboration with the project partner Camunda5. The key features and requirements for Ark Automate were derived from interviews with process experts, industry RPA developers, and researchers, revealing pain points of current RPA solutions as well as the needs of these diferent user groups, such as the discussed live monitoring and diferent modeling interfaces.
By using the open-source, text-based, and extendable Robot Framework, which is supported by the Robot Framework Foundation, a consortium of diferent companies, Ark Automate relies on a mature solution that is also used in industry to provide its RPA functionality.
In this paper, a novel open-source RPA tool, Ark Automate, was presented and ofered to the research community for use and further development.
Focusing on the modeling of RPA bots, it encourages to reconsider the current state of
RPA modeling. Building on the proven Robot Framework, the tool provides live monitoring
of running bot instances, and thereby enables new research directions, especially regarding
exception handling, a critical but neglected area in RPA [
While the internal data structure already supports more advanced constructs, it is planned to reflect this complexity in the interface as well, e.g., by supporting branching with if/else or reusable bot sub-processes, and to evaluate more interfaces, like flowcharts. Furthermore, the live monitoring and exception handling aspects will be strengthened.
We would like to thank Tobias Metzke-Bernstein and Daniel Meyer from Camunda for their support and feedback during the development of this project.