Value Chain Analysis is practical
Even after all these years I find the Value Chain model of Porter still one of the better, practical tools to analyse a process, its costs and its added value(s). Obviously the standard model has to be adapted for a given industry, for a given company / organizational model.
The model provides a framework for cost and added value dedicated actions.
Next to this Porter's 5 Forces model has proven to be a very practical business tool to make clear were a business is, where threats and opportunities are and therefor i.e. a help to weight energies, investments for the next period.