## 4 Research Deficit
### End-to-End Approach  
Regarding existing frameworks and standards for market demand flexibility, it must be pointed out that there is no approach covering information flows and automation from machines to energy markets. However, such an end-to-end approach from machines to energy markets is necessary to achieve consistency and interoperability with all technical entities and stakeholders involved.  
* Information flows: All bidirectional information flows between machines and energy markets, including every intermediate stage, must be covered to achieve an end-to-end approach. Bidirectionality because demand flexibility must be offered in the markets and, in addition,the purchase signals must subsequently be converted into load profiles within the company and ultimately into control signals for the machines and equipment. The information flows do not only cover company in-house processes as described by the automation pyramid [35; 53]. Therefore, the concept of the automation pyramid needs to be broadened to include external processes with regard to marketing demand flexibility (see Nos. 1 and 2, Section 3). In addition, decentralized approaches also need to be considered as these concepts are increasingly common and provide more flexibility for companies (Section 2.5.1).
* Multi-level optimization: In order to regulate complex information flows and control the efficient use of flexibility, different levels of optimization are necessary. These levels decompose the overall optimization problem of efficient flexibility usage into sub-problems considering characteristics such as planning horizons, temporal resolutions, and maximum permissible runtimes. It is important that optimization levels can be implemented dynamically, e.g., depending on the target process and the company's infrastructure, some of the optimization levels may be left out or split, e.g., into sub-optimizations. However, with decomposition, new challenges arise. First, restrictions made at certain levels must be respected by the following levels. Second, the-interaction between various optimization levels needs to be coordinated by a corresponding architecture (see No. 1, Section 3).
* Generic data model: To ensure consistency within the end-to-end approach for information flows and the interaction of different optimization levels, a generic data model covering a wide range of demand flexibility is necessary. However, not every communication between technical entities in the described end-to-end approach needs to be mapped in this data model. Rather, it is a matter of using the data model where it creates added value. Data models for further communication must then be designed in such a way that they can be derived from this generic data model or transferred back to it (see No. 2, Section 3).
* Traceability: While information flows and the data model ensure technical interoperability, the communication within the described end-to-end approach needs to be credible and trustworthy. Therefore, technical solutions meeting these specifications are necessary, e.g., step-by-step traceability of transactions. From a company-side perspective, this is to ensure that commercialized flexibility has really been implemented and the contract fulfilled accordingly. From a market-side point of view, the fulfillment of the contracts is equally important to ensure balanced groups in the energy system (see No. 5, Section 3).
* Encapsulation: Industry and the energy sector are completely different domains with diverse knowledge, methods, and technologies. To realize automated flexibility commercialization, both domains need to be connected and work interlocked. Consequently, approaches to encapsulate both domains without affecting the system's performance are necessary. This includes, but is not limited to, commercializing load profiles without revealing manufacturing secrets and ensuring free competition on markets, etc. (see No. 4, Section 3).