## 1 Introduction
The research focuses on minimum requirements for DCCs with clearly defined needs from laboratories and customers, following ISO 17025 [16; 17]. The DCC report will be presented in XML and includes information about the data, such as the uncertainty based on ISO GUM and the International System of Units. Metric conversion can be performed to meet the client's needs from a test laboratory or calibration laboratory. To avoid errors caused by human factors, software must automatically translate the data. Additionally, digital security measures have been enhanced to ensure the secure delivery of the DCC to the client, such as identity verification and software security. The use of XML enables machines to easily read the DCC, making it popular for Industry 4.0 and future digital metrology work [18; 19]. In conclusion, the DCC, an electronic certificate developed by PTB and NPL, meets the traceability and uncertainty requirements of the ISO 17025 standard and ensures secure delivery of the DCC to the client, and will soon replace paper calibration certificates (PCC) [20; 21; 22]. The digital transformation of the manufacturing industry has revolutionized processes, enhancing consistency, security, and efficiency through digital technology. By gathering and analyzing data automatically during production, digital technology facilitates data exchange, integration, and remote management and monitoring [16]. Industry 4.0, also known as the fourth industrial revolution, combines technologies such as IoT, AI, and extensive data analysis, using the Cyber-Physical System (CPS) concept to bring manufacturing and measurement processes into the digital realm [23; 24]. The PTB is focused on managing measurement technology to ensure calibration and traceability compliance [25]. To address this, PTB proposes using a standardized digital data exchange format, with XML as the common format, to publish a DCC based on SI units format. PTB has defined an XML data exchange framework, which ensures the interoperability and traceability of data in the conversion and transmission process. This approach will help address potential problems in the digital transformation of the manufacturing industry, ensuring compliance with calibration and traceability standards [10; 16; 23; 26; 27; 28]. Currently, users are requiredto manually input detected errors into compensation tables on various controllers. This manual process can potentially result in accidents, such as collisions involving knives or machine tools, due to abnormal compensation operations or programming errors. However, the utilization of XML files can facilitate the development and implementation of geometric error compensation for machine tool controllers, thereby enhancing the measurement precision of both machine tools and CMMs. It is crucial to emphasize that the values present in the DCC do not indicate the current parameters in the compensation tables. Residual errors or geometric errors represent the disparities between measured values and expected values, reflecting the remaining errors in the system after compensation. Geometric errors are particularly influential in the measurement accuracy of a five- or three-axis machine. International standard specification (ISO) 230-1 [29] and ISO 230-7 [30] identify 43 geometric errors in a five-axis machine, consisting of 21 errors of three linear axes and 22 errors of two rotary axes. For example, the hole plate [31; 32; 33; 34; 35] made of NEXCERA material from Krosaki in Japan is used to measure the CMMs with 21 geometric errors of three linear axes. [PERSON] et al. [35] utilized a hole plate to measure the CMM and developed a Monte Carlo simulation method for estimating uncertainty through computer simulation. By measuring and compensating for geometric errors, the CMMs and machine tools can be improved. [PERSON] et al.