Clemens William Pratt, 2 July 1936–16 January 2025

Clem Pratt was born in Brisbane in 1936 and died in Melbourne in 2025, aged 88 years. He is survived by his three children, grandchildren and great-grandchildren. He was President of the Statistical Society of Australia (SSA) from 1969 to 1971.

Clem was educated in Brisbane and was dux of Brisbane High School in 1954. At the age of 18, he enrolled in engineering studies at the University of Queensland, and then pursued postgraduate studies there and at the University of London, being awarded the degrees of BSc (Qld), BEng (Hons) (Qld), MEngSc (Qld) and PhD (London).

His background was primarily in queueing and congestion theory but also operations research more generally. He studied for his PhD (1961–1963) at Birkbeck College, University of London, under the direction of Professor (later Sir) David Cox; the topic for his dissertation was ‘Congestion Problems In Automatic And Semi-automatic Telephone Exchanges’.

In the 1960s, as an external part-time lecturer, he taught ‘Statistical Methods for Research Workers’ and ‘Operations Research’ at Melbourne University as part of the third-year Statistics course. I was fortunate to be one of his students and found his lectures inspiring. It was an early experience of the practical use of statistical theory.

Pratt helped set up the Victorian Branch of the SSA and was an early President of the Branch; it was during his tenure as President that the annual Belz Lecture was established in 1969. There were only three Branches of the SSA at that time (initially NSW, followed by Canberra and then Victoria).

Pratt had a 38-year career with Telstra (previously the PMG and then Telecom Australia), initially specialising in telephone traffic engineering, and later working in information systems planning and development, network operations, quality management and network planning. During this period, he represented Australia on several international bodies (including the International Telecommunication Union in Geneva and the Economic Commission for Asia & the Far East in Bangkok) and was on the governing body of the International Teletraffic Congresses. He also chaired the Board at the Teletraffic Research Centre at the University of Adelaide in the late 1990s. The Centre, incorporating the Centre for Defence Communications and Information Networks, conducted research and development for both the commercial and defence sectors.

In retirement, he lived in Melbourne where he enjoyed music, theatre, amateur astronomy and the company of his grandchildren and great-grandchildren. He became non-verbal in the latter years of his life because of a throat surgery but I was fortunate to have several email exchanges with him in late 2023 as part of my research for the SSA History Standing Committee.