How to create a cost benefit analysis in excel

This is for a for an Aviation/Aerospace System Analysis course. Here are the instructions:

Practical Exercise: Cost-Benefit Analysis
Consider, hypothetically, that you have already graduated with your Bachelor of Science (BS) degree and you are employed as the Warehouse Operations Manager at a medium-sized, aviation-related company that has 400 employees. The company sells aircraft electronics, airframe and power plant parts, and equipment to private, corporate, and commercial airline customers.

For this practical exercise activity, consider that a system request for a new Inventory Management System (IMS) had been submitted to you by one of your supervisors, which you forwarded to the company's Approval Committee for consideration. During the analysis that was conducted by the Approval Committee, it was discovered that companies can experience considerable savings when implementing such a system. Large enterprises like Proctor & Gamble have implemented an IMS and saved as much as over a billion dollars in one year.

After the system request had been thoroughly analyzed by the Approval Committee, it was selected to move forward and you are serving as the project sponsor/manager of the project. Feeling confident in your abilities as a result of the training in the SDLC process methodologies that you received 'back in the day' as a student at Embry-Riddle Aeronautical University (ERAU), you volunteered to serve as the project sponsor/manager.

You have five resources (team members) working with you on this project. One employee has been loaned to the team from the Information Technology (IT) department, one from the Finance Department, one from the Human Resources (HR) Department, and two are outside consultants that will be brought in at the starting point of the Analysis phase to assist with their process modeling and data modeling skill sets and experience.

At this point in the project, you are in the middle of conducting a Feasibility Analysis. You have already conducted a Technical Feasibility analysis and determined that the prospective users have a reasonable familiarity with the level of information technology and they could easily be trained, and the contract IT support unit is capable of installing, managing, and maintaining the inventory management system. Since you determined that it was technically feasible to implement the system, you will now proceed to the next step of the Feasibility Analysis in which you will conduct a Cost-Benefit Analysis.