There were anxious moments on Aug 21 when, out of the blue, the Prime Minister was taken ill midway through his speech at the National Day Rally. But while the worst might have been feared initially, it is fair to say there was no major panic over the possibility of the country facing an immediate leadership vacuum. The governing party has sought to avoid that over the years; Singapore's systematic and rigorous approach to leadership succession is a hallmark of its political system, laid down by founding prime minister Lee Kuan Yew.

That means around 20 new candidates must be fielded at every general election - a fifth to a quarter of the seats in Parliament. Crucially, there must be electable candidates with the potential for higher office. It also means setting high standards of competence and integrity for aspiring candidates and a rigorous selection process.

The current leadership has kept faith with this approach. Indeed, Mr Lee Hsien Loong made the point strongly immediately after he resumed his speech. "What happened makes it even more important that I talk about it," he said. "Nothing that has happened has changed my timetable or my resolve to press on with a succession. In the next GE (general election), we will reinforce the team again and soon after the next GE, my successor must be ready to take over from me."

Singapore is fortunate that there are in the Cabinet experienced ministers, including the two deputy prime ministers, ready to mentor and assess the contenders for the top job. They will be tested on their leadership ability, character and ability to connect with the people. The guidance they provide to younger colleagues will be invaluable. There are not many governments elsewhere with this culture of stewardship.

There are three areas which they will need to expose those with prime minister potential to. First, they have to be tested on their ability to tackle important national issues beyond their own portfolios. This will test their leadership abilities as well as expose them to the wider public. Second, they need to be able to connect with and mobilise people, especially when unpopular but necessary decisions have to be taken. Being able to carry the ground, particularly challenging in today's noisy social media world, is an important attribute of a prime minister in democratic societies. Third, they need greater exposure internationally so they can develop deeper relationships with their counterparts overseas. This is critical for Singapore which depends on its linkages with the outside world for its trade, investments and security.

Time is short; the process of grooming the next PM is urgent in the light of recent developments. Given its inherent vulnerabilities, most Singaporeans would prefer not to leave leadership transition to chance or the vagaries of the electoral process.