The S3M Quick Assessment Support Tool is provided by a master degree student as part of the assessment of his organization. It can help you use the maturity model and will enable you to do a quick process maturity assessment of your software maintenance organization.
Have a look at the publication of this student and how he used this simple Excel spreadsheet. The Excel spreadsheet is also available in the « Downloads » section of the site in the « Support tools and other references » look for « David-Alexandre Paquette short assessment tool ».