Electronic data processing

Electronic data processing (also: Information Technology or IT) can refer to the use of automated methods to process commercial data. Typically, this uses relatively simple, repetitive activities to process large volumes of similar information. For example: stock updates applied to an inventory banking transactions applied to account and customer master files booking and ticketing transactions to an airline's reservation system billing for utility services.

Early commercial systems were installed by large organisations. These could afford to invest the time and capital necessary to purchase hardware, hire specialist staff to develop bespoke software and work through the consequent (and often unexpected) organisational and cultural changes.

At first, individual organisations developed their own software, including data management utilities, themselves. Different products might also have 'one-off' bespoke software.

Data input required intermediate processing via punched paper tape or card and separate input to computers, usually for overnight processing. Data required validation in batches. Rejected data needed correction and resubmission with consequences for data and account reconciliation.

Data storage was strictly serial on magnetic tape: the use of data storage within readily accessible memory was not cost-effective. Very early computer installations also used delay line storage.

Results would be presented to users on paper. Enquiries were delayed by whatever turn round was available.