Estimation methods of parameters a and b can be found in Wang and Pham (2006) and Ben Hmida et al. (2010). Theorem: There exists an optimal PM period T* which minimises the average total cost per time unit
Estimation methods of parameters a and b can be found in Wang and Pham (2006) and Ben Hmida et al. (2010).Theorem: There exists an optimal PM period T* which minimises the average total cost per time unit