The objective of this workpackage is to define a model for (i) assessing the effort of software modification, (ii) identifying healing actions following practices from the Squale quality model defined in the previous workpackage (WP1.3). It defines the input for the next workpackage which is about planning actions once their effort is characterized. The key constraints of this work are: • The remediation effort should be expressed in the context of a quality model. It should act as a quantification of the work to obtain a better (or good) quality of the entity under analysis. • The remediation should be based on practices as described in the workpackage 1.3.