When I was completing my PMP application, back in 2006, I recall reading the eligibility requirements and asking myself where I had the greatest gaps in my project management experience. PMI did a good job of listing the process groups and activity "buckets" in which I could associate my time. To visualize my strengths and weaknesses, I identified each activity provided by PMI as a process group subcategory and then associated project hours within a spreadsheet. Though PMI had a requirement that I document experience in each of the process groups, I had a personal requirement that I improve where my skills were lacking. This post isn't about my strengths or weaknesses, though you could assume by the graph that it would be Initiating and Closing. It is about my identifying my experience gaps and helping you identify yours (in the eyes of PMI). If you're a PMP or an aspiring PMP, take a look at the attached.
Step 1: Review the Process Group Activities PDF. It will define the subcategories.
Step 2: Associate subcategory hours on a project basis. The formulas are already in the worksheet. All you need to do is add your hours to the Project Data sheet.
Step 3: Review the Graph on the tab titled "Graph". If you don't identify your strengths and weaknesses from the data sheet, you will certainly see them in the graph.