How to evaluate a legacy software application for purchase

Buying a software business can be tricky because you can’t actually see software.  The web application might look good, might function as expected but be so poorly built that it is likely to fall apart right after you take over.  Buying a software based business, especially a SaaS, requires an inspection, just like buying a house.  Below are a few thoughts that we passed along to me from my friend at Dive Create (A Columbus, Ohio based UI/UX firm).


Information Technology
·         Census of backoffice systems including current contracts, spend and term for accounting, support, marketing, sales, R&D, etc.
·         High level overview of all application software – provide description and key functionality area
·         Inventory of technical infrastructure – Hardware, Software, Databases, Network / Communications Equipment
·         Network diagrams – Internal & SaaS systems
·         Disaster recovery plans
·         IT organization chart – with roles & responsibilities
·         Policies and procedures documentation
·         Systems data backup policy and process (Frequency, format, rotation, storage, testing)
·         Key IT vendor contracts
Application Development
·         High level architectural diagram
·         Database documentation (database names, purposes, and schema)
·         Full technology stack used (.net/java, sql server/oracle, knockout/angular, etc.)
·         Description of any external system interfaces
·         Operations manuals
·         User manuals
·         Development methodology documentation
·         Testing methodology
·         Current issues log
·         Application enhancement roadmap
·         3rd party tools/systems used along with current contracts/agreements for them
·         Open source software used