Why was the "Dispatch Reliability" of the A320 "low" during its first years?

Question

I found the following Statement on the German Wikipedia page about the A320 family of aircrafts.

Nach erheblichen Schwierigkeiten in den Anfangsjahren erreicht die A320-Familie mittlerweile eine Abflugzuverlässigkeit von 99,7 Prozent. (https://de.wikipedia.org/wiki/Airbus-A320-Familie#Wirtschaftliche_Aspekte)

This roughly translates to:

After significant difficulties in its early years, the A320-family reaches a Dispatch Reliability of 99.7% nowadays.

I could not find more information about this statement, so my question would be why the Dispatch Reliability of said aircraft family was supposedly significantly lower in its early years? Is it normal for completely new types of aircraft to have such a low DR that it's worth mentioning?

Answer 1

The A320 saw entry into service on 18 April 1988 with Air France.

About a year later Flight International covered the dispatch topic. For British Airways – whose initial acquisition of the A320 was through the British Caledonian takeover, and not an order – the problems weren't with the plane, but with the Boeing culture that had to adapt.

Otherwise there was nothing notable.

(...) The "culture difference", says Bracken, materialised in apparently trifling (but actually problematic) ways, such as line mechanics having trouble with Airbus literature. There was nothing wrong with the literature, it was just different.

November 1 came. "It wasn't a very good start," says Bracken, "but the reasons were outside the aircraft." By January, BA's A320 technical dispatch rate had not climbed out of the 96 per cent range, reveals Barry Gosnold, chief engineer technical services.

That is a revealing figure. BA had expected much more, even though the performance is not unusual for a completely new aircraft.The A320's performance with Air Inter at the same time was between 2 and 3 percentage points better, although Air Inter had received its first A320 months later than BA.

Source: AIRBUS A320 AT WORK, Flight International, 17 June 1989

Answer 2

The A320 was innovative in a number of ways, especially its Fly By Wire control system, and now it is an incredibly popular and mature platform, partly because of its despatch reliability.

All the elements that allow a despatch of the aircraft for a commercial flight contribute to despatch reliability. This can be anything from having spare parts for anything that needs to be replaced, to crew being familiar with inspection and preparation procedures (checklists) for the aircraft, to pilots correctly understanding messages on the flight management system.

When aircraft are first introduced, there are often problems with logistics and the (unintended) interactions between aircraft systems. As the aircraft accumulates more operating hours, these problems get solved. As aircraft reliability improves over time, it can also be safe to operate in "MMEL" conditions (master minimum equipment list).

For example, if you know it is safe to despatch with a certain warning message because you have proven that the 3 redundant backup systems are functioning properly - this further helps despatch reliability, because now you know it is safe to dispatch whereas on day one with the new aircraft, you did not have that option.

When I worked as a supplier to two major airframers, they were always incredibly keen to improve despatch reliability by fractions of a percent.