Fig. 1. Components of ISO/IEC 15504.

Fig. 2. An overview of the ISO/IEC 15504 two-dimensional architecture.

Fig. 3. Relationship between the reference model and the assessment model.

Fig. 4. The relationship between indicators and process attribute ratings.

Fig. 5. Types and examples of response categories.

Fig. 6. Primary business sector of OUs participating in the trials and that have used Part 5.

Fig. 7. Approximate number of IT staff in participating OUs that have used Part 5.

Fig. 8. Employment status of (lead) assessors.

Fig. 9. Experience of assessors with assessment models and methods.

Fig. 10. Software engineering and assessment experience of the (lead) assessors.

Fig. 11. The number of assessments where the assessors participated in the past three years.

Fig. 12. Schematic showing the tasks involved in multiple imputation.

Table 1. Summary of the process categories

Table 2. Overview of the capability levels and attributes

Table 3. The four-point attribute rating scale

Table 4. The aggregation scheme for converting ratings on the individual attributes into a capability level

Table 5. Region where the 57 assessments were performeda

Table 6. Usefulness and ease of usea

Table 7. Meaningfulness of rating and aggregation schemea

Table 8. Usability of ratiing scalea

Table 9. Usefulness of indicatiorsa

Table 10. Understanding the process dimensiona

Table 11. Understanding the capability dimensiona