When looking for existing capacity, think of consulting your local counterpart(s) as well as other national and international stakeholders as a first step.
When attempting to look for existing capacity, your first stop should be your local counterpart. Your counterpart will be able to provide you with an overview of existing capacity and structures, explain the context and history behind such capacity, highlight gaps and offer possible solutions. Soliciting your counterpart will also send the message that you are open and willing to learn, that you genuinely seek and appreciate their input, and that you are actively engaging them in your mission. In addition to offering the required information, this can significantly contribute to building a positive relationship with your counterpart.
Apart from your local counterpart, you should also seek to consult other actors, both national and international, who work on related issues. The multiplicity of sources will result in a multiplicity of ideas and opinions that will provide you the raw material to develop your own opinion.
However, when engaging in discussions with other actors, you should pay attention to your interview style. First, you need to ask focused questions that will enable you to assess existing capacity without being accusatory. For example, how something is accomplished, with what means, how developed is the approached etc.
Second, you need to ask your interlocutor for data rather than analysis. Many of your interlocutors will be enthusiastic to tell you how good- or bad- a project is. You should try to focus your discussions on how things work and develop your own analysis at a later stage.
Third, you should refrain from questions that are suggestive, judgmental or assign blame.