Pursuing efficiency in business: the technological and commercial development of LEO Computers

LEO Computers were a series of machines designed, developed, and manufactured for business applications between 1947–1969 by the British catering firm J. Lyons & Co. and its subsidiary LEO Computers Limited. This dissertation takes LEO Computers as a case study for understanding the emergence of business computing, aiming to analyse both how the introduction of computers affected commercial enterprises and how computer design changed because of the new requirements of business data processing.
The theme of efficiency, chosen to guide this research, explains why a food and teashop company decided to enter the computer industry in 1947. To achieve a working machine in the shortest time possible, Lyons opted for a joint venture with Cambridge University which was developing its ED-SAC computer. Lyons adapted the Cambridge machine’s architecture, designed for scientific computing, to make it suitable for their business purposes. Lyons’ business practice was rooted in Scientific Management theory which influenced the applications, design and programming choices of the LEO team. Their quest for efficiency through improvement of processes and methods, combined with their philosophy of vertical integration, led to the construction of their first computer, LEO I, operational in 1951, and to the establishment of LEO Computers Limited in 1954 as a reaction to outside demand for purchase of LEO machines. To ensure efficient and reliable computing they developed a series of procedures consisting of hardware testing, data validation and program correctness techniques. From 1962–64, at the peak of its success, but fully aware of an incipient financial crisis, LEO was involved in an attempt to create a consortium of computer manufacturers to set against IBM’s strong presence in the European market. This partnership failed to materialise and Lyons sold their computer interests: LEO Computers was involved in a series of mergers in the British computer industry, culminating in the establishment of International Computers Limited prompted by the British Ministry of Technology in 1968.
This thesis represents an academic analysis of LEO Computers: existing literature generally consists of either first person accounts or articles and books aimed at a more general readership. This analysis is aimed at computer and business historians and at computer practitioners with an interest in history; combining a historical and technical approach. Existing narratives and accounts are reconsidered here in the light of new archival sources and perspectives, and the technical examination of dependability provides a fundamental and complementary analysis to advance the understanding of LEO’s significance in the history of computing.