Why is it important to measure maintainability, and what are the best ways to do it?

Software both enables and challenges companies to keep up with the increasing rate of changes in technology, competition, organizations, and the marketplace. Although much of the software engineering literature is focused on software development, Koskinens 2009 survey found that 75--90% of business and command & control software and 50--80% of cyber-physical system software costs are incurred during maintenance. Knowing how maintainable a piece of software helps in the following situations: • Deciding whether and what parts of existing software to reuse; • Deciding whether to maintain or redevelop software components; • Estimating the amount of effort involved in maintaining software components; • Determining award fees, acceptance criteria for Turnkey software; • Providing evaluation data for reuse repositories; • Saving a significant fraction of total software ownership costs.