Use EdrawMax to create an interrelationship diagram for your business needs. The free interrelationship diagram comes with hundreds of symbols and predefined templates that let you design the business relationship diagram as per your need. The best way to understand the factors affecting the sales problem is to create a relationship diagram showcasing the major factors. As the diagram represents, the major factors are the quality of product, the pricing of your product, the customer care service, quality of salespeople, budget for sales activities, lack of honest employees, and lack of collaboration across departments.