# Simultaneous Use of Digital Technologies and Industrial Robots in Manufacturing Firms
## 3 Research Methodology
### Industry 4.0 Readiness Index  
The proposed Industry 4.0 readiness index in our research was developed by Fraunhofer ISI [40]. The logic of the Fraunhofer Industry 4.0 readiness index is presented in Figure 2, and it is based on the selected Industry 4.0 enabling technologies. For this index, we are using digital (enabled) technologies that are highly process and operation-dependent and come from different technology fields. Therefore, it is not sufficient simply to count the number of technologies used. Based on the technology focus, they are divided into 3 technology groups:  
* Digital management systems: this group consists of software systems for production planning and scheduling (also known as Enterprise Resource Planning systems; ERP) and product lifecycle management systems (PLM);
* Wireless human-machine communication: the second group consists of digital visualization technologies and mobile devices;
* Cyber-physical system (CPS)-related processes: the CPS group consists of near-real-time production control systems, technologies for automation and management of internal logistics, and technologies for the digital exchange of data.  
Figure 2: Industry 4.0 readiness index.  
The first 2 technology groups cover typical ICT-related processes (ERP and PLM systems, technologies for digital visualization and mobile devices) that, by themselves, cannot form the Industry 4.0 concept. On the other hand, CPS-related technologies already had production elements in cyber-physical systems and are therefore considered to be among the advanced I4.0 technologies [40].  
Based on the presented grouping, manufacturing firms can be classified into different levels of readiness for the Industry 4.0 concept. Some firms still do not use any Industry 4.0 enabling technologies (non-users), with no signs of digital production. Included in the Basic readiness group are manufacturing firms that use mostly digital technologies from Digital management systems and Wireless human-machine communication fields. The number of technologies can vary; therefore, there are 3 basic levels. In the 3 rd level, it is assumed that firms also use 1 CPS-related process. The High readiness group consists of firms that use and combine several technology fields in production and, at the same time, use several of the CPS-related processes in their production. Accordingly, the Industry 4.0 readiness index results in the following main groups and levels:  
Non-users who are not (yet) ready for Industry 4.0:  
* Level 0: Firms that do not use any of the Industry 4.0 enabling technologies and tend still to rely on traditional production processes;
* Basic levels, as the basis on the way to Industry 4.0, with little readiness;
* Level 1 (beginners): Firms that use IT-related processes in 1 of the 3 technology fields;
* Level 2 (advanced beginners): Firms that use IT-related processes in 2 of the 3 technology fields;
* Level 3 (advanced users): Firms that are active in all 3 technology fields and use both IT-related processes and 1 technology in the CPS-related group;
* Top group, firms on the way to Industry 4.0, with a slightly higher readiness:
* Level 4: Firms that are active in all technology fields and use at least 2 technologies of CPS-related processes;
* Level 5: Firms that are active in all technology fields and use at least 3 technologies of CPS-related processes;  
With each level, the Industry 4.0 readiness status increases, or the distance to digital production decreases. However, even at levels 4 and 5, it cannot be assumed that these are firms that embrace the Industry 4.0 concept fully. Nevertheless, the presented Industry 4.0 readiness index maps the change from traditional production to production close to Industry 4.0 [40].