Overhead is a word created from the English words over and head and can be translated as overhead. The term overhead is used in information technology, data processing and transmission, and in business administration.
- In information technology and data processing, overhead is about data. It is understood to mean the data that does not belong to the user data and is used for filling purposes, control functions or control functions, such as parity checking. In order not to store unnecessary data on storage media, one tries to keep the additional data as small as possible.
- In communication, overhead (OH) refers to all information that is transmitted in addition to the user data. This is data that is technically required, such as the header in data packets, routing and control data, data for error correction, check characters, etc. The overhead also contains information about the network state or operating instructions, routing information, and returned user data containing errors. The ratio of user data rate to overhead determines the transmission performance.
- In data transmission, overhead consists of filler data to meet certain protocol specifications, for example. This is the case when data packets have a specified frame length that cannot be filled with the user data. The data for a reception check, which is used to determine whether the correct recipient has received the data packets, also counts as overhead data.
- In business administration and project management, overheads belong to the overhead costs. Depending on the project, they are allocated from the administrative and personnel costs, the costs for insurance, mobility and communication as well as for material and operating resources. Overhead costs are divided into costs that can be directly allocated to the project, i.e., true overhead costs, and costs that cannot be allocated. These are called non-genuine overheads. In the case of non-genuine overhead costs, cost allocation may be too cost-intensive and may not be in any relation to the calculated overhead costs.