Seems like this is a very common problem for beginners with CodeIgniter, but none of the solutions I\'ve found so far seems very relevant to my problem. Like the topic says I\'m
Including a class file is not a bad approach.
In our projects, we do the same, add an another layer to MVC, and thats a Service Layer which the Controllers calls and Service calls the Model. We introduced this layer to add Business Logic seperate.
So far, we have been using it, and our product has gone large too, and still we find no difficulty with the decision of including files that we had made in the past.