I want to identify team members' weak and strong points, in order to work on the team's (and individuals') signature. Are there known techniques for building team members' profiles (maybe similar to Roleplaying Game character sheets) and refining them over time?
You need to identify:
- What skills are needed for your current team to be successful?
- What skills does every individual wants to improve on?
And then find a common ground to figure out the right skills,levels and how to proceed. A good idea as Liath pointed out is to let the team build this matrix together.
I looked at Anton suggestion, a competency matrix is a great idea, but you also need to include soft skills on them because they tend to be equally valuable for a great team to succeed.
Another point, be very wary of creating diverse skills that are not easy to game, and that ideally evolve /change a bit overtime, otherwise people might just rapidly lean towards improving the skills you consider useful and then forget about improving themselves. More information on this topic can be found in the book: Drive.
Have a look at the Agile Skills Project. It touches on all skills which Agile development team members might need. You can do a self or peer assessment. After the assessment they can look for gaps and the Scrum Master can coach them to get deeper skills in those topics.
It works similar to a more typical skill matrix, but it helps you get started with a broad set of Agile skills, in the following areas: Business Value, Collaboration, Confidence, Product, Self Improvement, Supportive Culture, Technical Excellence