Product software implementation method result in ambiguity when questions arise in the execution of the implementation process. On the other hand methods can be used as a profession, meaning that the method should be taken strict and the usage of the method should be a profession, instead of a guiding principle. This view is very useful if the implementation process is very complex and is very dependent on exact and precise acting. Organizational and quality management will embrace this view, as a strict usage of any method results in more clarity on organizational level. Change management however might indicate that more flexibility in an
Linear multistep method of a one-step method depends on the initial condition formula_73, but the numerical solution of an "s"-step method depend on all the "s" starting values, formula_74. It is thus of interest whether the numerical solution is stable with respect to perturbations in the starting values. A linear multistep method is "zero-stable" for a certain differential equation on a given time interval, if a perturbation in the starting values of size ε causes the numerical solution over that time interval to change by no more than "K"ε for some value of "K" which does not depend on the step size "h".