Come Sept 1, the Civil Service will, for the first time, be helmed by a chief who began his career as a policeman investigating crimes.
Mr Leo Yip, 53, will take over from outgoing Civil Service head Peter Ong, 56, who is also Permanent Secretary (Strategy) in the Prime Minister's Office (PMO).
Mr Yip rose to the rank of commander of the Clementi Police Division before becoming the force's director of planning and organisation, and then of operations.
In 2000, he was made principal private secretary to then Senior Minister Lee Kuan Yew.
He moved to the Ministry of Manpower in 2002, and was appointed its permanent secretary in 2005, before becoming the Economic Development Board's chairman in 2009.
He was made Permanent Secretary for Home Affairs in 2014.
Changes at a glance
PETER ONG, 56
• Retiring and stepping down as head of the Civil Service and Permanent Secretary (Strategy) in the Prime Minister's Office.
LEO YIP, 53
• Will be appointed as head of the Civil Service and Permanent Secretary (Strategy) in the Prime Minister's Office.
• Keeps his appointments as Permanent Secretary (National Security and Intelligence Coordination) and Permanent Secretary for the Prime Minister's Office.
• Relinquishes his appointment as Permanent Secretary for Home Affairs.
PANG KIN KEONG, 51
• Will be appointed Permanent Secretary for Home Affairs.
• Relinquishes his appointment as Permanent Secretary for Transport.
LOH NGAI SENG, 46
• Will be appointed Permanent Secretary for Transport.
• Relinquishes his appointment as Second Permanent Secretary for Home Affairs.
LAI CHUNG HAN, 44
• Will be appointed Second Permanent Secretary for Home Affairs.
• Keeps his appointment as Second Permanent Secretary for Education.
Last year, he took on two more roles: Permanent Secretary for the PMO and Permanent Secretary (National Security and Intelligence Coordination) in the PMO.
Mr Yip will take over Mr Ong's portfolio and give up his post as Permanent Secretary for Home Affairs.
In a statement, the Public Service Division paid tribute to the outgoing chief, Mr Ong, who served for more than 31 years in the public sector and assumed the top post in 2010. He "led with distinction in his various permanent secretary appointments", said the PSD.
Mr Ong praised his colleagues, saying: "They are people who serve the public with the utmost dedication, professionalism and integrity. I saw this everywhere I went in my 31-year journey across the various ministries and organisations."
He was permanent secretary in the ministries of defence, transport, trade and industry, and finance from 2000 to last year.
As Permanent Secretary for Transport, he oversaw the opening of the North-East Line, the deregulation of the taxi industry, and measures to strengthen aviation and maritime competitiveness.
The PSD also credited him for the key role he played in crafting policies that steered the economy through some difficult years, including the 2008-2009 global recession.
And as the Permanent Secretary for Finance, Mr Ong oversaw the successful implementation of several national Budgets. They included key measures such as the Grow and Share package in 2011 to share the fruits of economic growth, the Pioneer Generation Package in 2014 to help with seniors' healthcare bills, and the MediShield Life universal insurance scheme in 2015.
Deputy Prime Minister Teo Chee Hean, the minister in charge of the Civil Service, thanked Mr Ong for his "outstanding leadership", and praised him for building a bold and innovative public service.
Mr Ong also guided the public service's move towards digital government, and used technology and data to craft better policies and serve Singaporeans, said DPM Teo.
He added that he looked forward to Mr Ong "continuing to contribute in different capacities".
Replacing Mr Yip as Permanent Secretary for Home Affairs is Mr Pang Kin Keong, 51, who has held posts in the trade and industry, home affairs, and law ministries.
Mr Pang will relinquish his appointment as Permanent Secretary for Transport, a post that will be filled by Mr Loh Ngai Seng, 46, who cut his teeth in the defence, education and home affairs ministries.
Mr Loh's existing position as Second Permanent Secretary for Home Affairs will be taken up by former navy chief Lai Chung Han, 44, who will continue as Second Permanent Secretary for Education.