A Community-Developed Measurement of the Reusability of Software Through Reuse Readiness Levels

When software is developed with reuse purposes in mind from the start, the resulting product will often be more mature, in a reuse sense, than products which are modified for reuse purposes after they have been developed. But it can be difficult to assess the maturity level of a software product due to the variety of factors that influence its reusability. If these factors could be measured, assessed, and combined into a single scale measuring the maturity of the software in terms of reusability, it would be of great benefit to developers. They will more easily be able to determine how ready the software is for their purposes, and how much modification may be necessary before it can fill their needs. The NASA Earth Science Data Systems (ESDS) Software Reuse Working Group is in the process of developing a set of Reuse Readiness Levels (RRLs) for the purpose of determining the reuse maturity of software assets. These levels are modeled after NASA's Technology Readiness Levels (TRLs), which have been used for many years, particularly for assessing hardware's readiness for spaceflight purposes. To assess the reuse maturity of software, a number of factors are included in the Working Group's development of the RRL scale including portability, extensibility, documentation, support, packaging, intellectual property and licensing issues, standards compliance, verification and testing, and modularity. Members of the working group have described the levels reusable software goes through as it becomes more mature in each of these areas. These individual levels will be combined into a single RRL scale that will allow a single number to describe the reuse maturity of software. This presentation will describe the Working Group's efforts in the creation of the Reuse Readiness Level (RRL) scale.