Poll on views of the different models by which companies can access software tools and functionality.
Ownership may have initially higher costs, but lower long term expense. It can be used whenever and for however long the user wants. There is no dependency on a third party or external network.
SaaS offers lower initial costs, but can cost more overall. Easier to change loading as project changes. No internal management. Dependent on external provider.
Cradle - 3SL's Requirements Management and Systems Engineering tool