Cost of punctuality

Every so often we hear airline or industry experts talk about cost of delays or disruptions. But, what about cost of flight punctuality? Airlines could spend fortunes to cover up for internal errors and external destructions by hiring replacement aircraft in order to keep their schedules on time, add more crew, spare parts, equipment, invest in information systems and so on. These ‘punctuality costs' are not associated with flight delays or, more generally, disruptions. So, how much good punctuality really cost airlines? Is it worth investing too much in improvements of on-time performance, when relatively high percentage of faulty services has already been accepted as an industry standard? Airlines obviously need to find the optimum balance between punctuality and investment in its improvement.