Service productivity and service quality: A necessary trade-off?

This paper is about service productivity and perceived service quality. Both a high service productivity and a high customer perceived quality are two main drivers of good performances in service companies and they simultaneously occur as a consequence of a synergy of several drivers such as employees' competences and motivation, organizational efficiency, technical devices availability, information technologies employment, etc. In scientific literature a trade-off between productivity and perceived service quality is asserted and several cases derived both by market observations and academic research could bear such trade-off out. But, is it possible to state that, under some circumstances, such a trade-off between productivity and perceived service quality could be avoided? And if yes, why such certified substitution should not work?