A successful completion of SCAMPI B provides vital information on the status and progress of preparation of the organization undergoing SCAMPI B. It is an indicator for the status of the effort of the resources and status of the artefacts produced as evidences.
But SCAMPI B certainly is not an assurance for SCAMPI A success. Instead it provides indicators for the different activities and evidences and provides opportunities for improvement.
Using SCANPI B organization can be used for detailed input on their Compliance and Non-Compliance for different activities.