Devise helpdesk classification system for online charity services

An online service focused on providing free services to charities needs to create an online help desk application that allows charities to lodge tickets for advice on issues facing them. In order for the help desk to work efficiently, we need a way to classify the tickets. By classifying the tickets, we can make sure the ticket is sent to the right person (e.g. a question about website design goes to the person who is an expert in web design). We need to develop four layers of classification: top-level, middle-level, lower-level, and keyword. Top-level relates to the overall category: “what is the field?”. A relevant example is “Fundraising”. The middle-level relates to the topic area within the overall category: “what is the topic area?”. Relevant choices could include Fundraising Strategy, Donor Relations, Fundraising Channels, Gifts and Grants Advice. The lower-level is the detail. Assume the user selected Fundraising Channels. They could then be presented with the following choices: Online Fundraising, Telephone Fundraising, Direct Mail Fundraising, Event-based Fundraising, Corporate Fundraising. The keywords indicate the specific area of interest. If the person selected Online Fundraising – they could specific the particular area (e.g. Website Design, Online Newsletters, Payment Processing). The listing needs to follow the MECE principle ([login to view URL]). We expect there will be around 7 top-level categories. Each of the top-level categories will have around 5 middle-level categories. Each of the middle-level categories will have around 5 lower-level categories. Each lower-level category should have around 5 keywords. We need the person who develops the classification to identify relevant categories and keywords for us to ensure charities can always find something relevant to classify their help desk ticket.