Cities readily associate new infrastructure with progress. When a highway is built or storm water canals are upgraded, the change is visible and the benefits, tangible.
But for maturing cities, the unseen and often thankless task of maintaining existing infrastructure can be more pressing.
National Development Minister Lawrence Wong said at an R&D conference in June: "As we started out as a new city, all of our infrastructure was very new… Singapore is now more than 50 years old. We are still very young by international standards, but we are coming to a stage of development where our infrastructure is ageing. So we need to ensure that this ageing infrastructure remains well-maintained and effective throughout their lifespan."
The Centre for Liveable Cities recently studied how organisations excelled in this never-ending marathon of ensuring infrastructure stays reliable, speaking with PUB and PSA - organisations with a proven record in maintaining Singapore's water and port systems.
Singapore's national water agency, PUB, is the statutory board managing the nation's water supply, water catchment and used water in an integrated way. Among the assets it oversees are 5,500km of potable water pipelines underground.
Leaks in these pipelines decreased from about 20 leaks per 100km annually in the 1990s to below six today. This is lower than Munich, Germany (seven leaks per 100km), Anglian Water, Britain (13 leaks) - which supplies the east of England - as well as Toronto, Canada (25 leaks) and Sydney, Australia (26 leaks).
Home-grown global port operator PSA International is the world's largest port group by equity-weighted throughput, with a network of 40 terminals in 16 countries, including the world's busiest container transshipment hub in Singapore.
PSA's assets in Singapore include 230 quay cranes, 700 yard cranes and 1,300 prime movers.
Even as PSA invests in new technology and intelligent systems, it upkeeps its equipment fleet rigorously to ensure high performance. PSA's cranes have improved in reliability, under the Mean Moves Between Failure indicator, by an average of 6 to 7 per cent annually between 2009 and 2016.
The two organisations' experience in consistent maintenance can be summarised in five broad principles - principles which can apply to other sectors that upkeep physical assets.
First, the asset must be well-understood.
This means collecting and analysing data to shed light on variables like lifespan, points of failure, and probability and consequence of failure. This helps determine the most sensible maintenance strategy.
In one of its maintenance frameworks for electrical and mechanical equipment, PUB looks out for the "age-related" failure pattern versus a "random" pattern.
An "age-related" pattern, where an asset has high failure probabilities at the end of its life, is best met with a strategy leaning towards replacement.
But a "random" pattern is better dealt with through regular condition monitoring of equipment, says PUB.
The second principle: Proactive inspections, with both preventive and predictive elements.
Preventive checks are those done at regular intervals. Predictive checks involve a constant monitoring of alarm-triggering indicators, based on an evolving understanding of the equipment. Proactive inspections yield early prompts for corrective measures, hence avoiding problem escalation.
PUB will adopt acoustic and sensor technologies to identify weak sections in buried pipelines, to replace them pre-emptively.
PSA, too, knows which gear reducers and wheel bearings to retire early by putting them through infra-red thermography and deleterious particle counter testers.
The third principle: Having a feedback loop between the maintenance team and the team that designs and installs.
Designs that look good on paper may yet be costly to maintain, so the maintenance team's views must be factored in early.
At PSA, cross-departmental teams look at major procurements to consider issues of maintenance and integration with existing equipment.
At PUB, maintenance data prompted the move away from cast iron pipelines to more durable ones such as ductile iron and steel pipelines. PUB's manpower rotation system also means a maintenance officer could be rotated to the design and construction team, and vice versa, promoting seamless cooperation across teams.
The fourth principle: Consider costs in a long-term, life-cycle way, thinking about capital expenditure (how much to design and build) and operating expenditure (how much to operate and maintain). Sometimes, more upfront spending or replacing an equipment can reduce overall costs.
It also means anticipating sudden expenditure increases when, say, a cohort of an asset needs replacement all at once.
PUB is integrating finance and maintenance data on a single IT platform to give a holistic picture of life-cycle costs.
It is also cognisant of a sizeable cohort of potable water pipelines due for replacement in roughly 30 years' time. To avoid a crunch, PUB has begun ramping up renewal, starting with more leak-prone pipes. Last year, it renewed 20km of these pipelines.
This rate will more than double to 50km annually by 2019.
PSA's life-cycle costing takes into consideration how some equipment spare parts are costly to procure after a certain point.
The final principle: Having professional, motivated maintenance staff.
This includes skilled technicians who know the equipment intimately and complete maintenance tasks with competence and care.
It also includes professional engineers making strategic, network-wide maintenance calls, and leveraging on data and technology to improve the maintenance regime over time.
PUB staff receive training throughout their careers through its Water Academy. The rotation system mentioned earlier exposes officers to a wider range of functions, broadening their experience.
By engaging state-of-the-art technology and innovations, PUB also seeks to remain an exciting place for young engineers, to encourage them to stay on to be part of the changes.
PSA maintenance staff stay future-ready through its skills framework under the PSA University. It can also put new hires through an in-house, accredited two-year course leading to a Higher Nitec certificate in port equipment.
In the new phase of Singapore's journey as a city, maintenance may well become the central task for public and private players in the built environment sector. After all, what was built in the first 50 years must be maintained in the second 50 years, and beyond.
Organisations with physical assets to manage will do well to learn from PUB, PSA and other relevant examples at home and abroad.
- The writers are researchers at the Centre for Liveable Cities.