The world's most punctual airports and airlines for 2020 revealed

(CNN) — Aviation punctuality reports are a bit like buses; you wait all year for one then two appear at once.

On Thursday, travel data analyst Cirium released its annual On-Time Performance Review, naming Russian flag carrier Aeroflot the world's most on-time global mainline airline and Moscow's Sheremetyevo International Airport the world's most punctual airport.

Then on Friday, rival data analyst OAG unleashed its Punctuality League 2020, declaring Indonesia's flag carrier Garuda Indonesia the world's most punctual airline, Aeroflot the most punctual mega airline in Europe and Sheremetyevo International Airport the world's most punctual mega airport.

So why the discrepancies? What's the difference between a mega airport and a small one? And why is Russia doing so darn well? Join us as we crunch down the results.

Indonesian flag carrier Garuda Indonesia has been named the world's most punctual airline by OAG.

ADEK BERRY/AFP/Getty Images

The two analysts calculate their results using similar data sources -- Cirium tracks more than 100,000 flights per day, OAG's league is based on 57.5 million flight records using full-year data from 2019 -- but with slightly different categorization. The bigger the airport, the busier the airline, the greater the distances involved, the more challenges to face, and both analysts take this into account when weighing up the performance of airlines and airports.

"Airlines don't always get the credit they deserve for delivering such a complex product," says Cirium in its review.

"Ensuring a seamless customer experience requires vast effort around the clock by a dedicated 'army' of ground staff, flight crew, cabin crew, engineers, ground service agents and many more companies besides within a vast supply chain. They also have to contend with many factors beyond their control, such as inclement weather and air traffic control issues."

People stand in front of Sheremetyevo airport terminal F in Moscow on June 26, 2013 where US intelligence leaker Edward Snowden on June 26, 2013 spent a fourth day with his onward travel plans still a mystery as Ecuador warned it could take months to consider his asylum request. The man responsible for one of the biggest intelligence security breaches in US history has not been sighted since arriving in Moscow on a flight on June 23 from Hong Kong and according to Russia is still in a transit zone at Sheremetyevo airport. AFP PHOTO / KIRILL KUDRYAVTSEV (Photo credit should read KIRILL KUDRYAVTSEV/AFP/Getty Images)

Moscow's Sheremetyevo is feeling the benefits of a new third runway.

KIRILL KUDRYAVTSEV/AFP/Getty Images

It's considerably easier for an airport with fewer than five million departing seats per annum, such as Minsk, the world's top small airport according to OAG, to ensure that 92.6% of its flights depart or arrive within 15 minutes of schedule, than a mega airport handling more than 30 million departing seats.

The excellent performance of mega airport Sheremetyevo, which handles more than 300 flights per day, can in part be attributed to a new third runway adding increased capacity.

Cirium said,"Aeroflot, the largest carrier at the airport maintains nearly 84% of the total operations at SVO. With a carrier owning such a lion's share of operations at one airport, it stands to reason that as Aeroflot goes, so does SVO."

John Grant, senior analyst with OAG, commented in a press release on an impressive year for punctuality. "The global market is reaching near peak [on-time performance].

"The rise [...] is led by Mega Airlines like Aeroflot, Delta and Air France, which are simultaneously expanding the number of operated flights and maintaining high OTP. We're seeing success trickle down to the hubs they service, which benefits the entire travel ecosystem."