I want to build optical management software

Software 1. Creating a Super Administrator 2. Creation of a center - shop 3. Creating an administrator 4. Creating the list of doctors 5. Creating the list of sellers 6. Creating the list of secretaries 7. Creating the tax list (VAT / VAT) 8. Creating a calendar for appointments (synchrome with Google Calendard) 9. Creating the supplier / manufacturer list 10. Create list of glasses or hearing aid (eg Widex, battery, charger) When a customer enters the shop, the secretary asks for her name, searches the database, if she finds, we have her file, the list of her purchases, her problems, her doctor ..., otherwise, we create a file. If the client wants to order corrective glasses, we scan the doctor's prescription, we create a proforma-invoice (quotation), we order the glasses, the frame, the storage box ... we create an appointment in the agenda. When the customer picks up his order a few days later, we transform the quote into: Delivery note, warranty certificate, invoice ... Another customer arrives at the shop with an appointment, we warn the seller by the notation icon on his computer, we find in the agenda the reason for his visit, for example, Repair, Breakdown, Refund request, get his order , payment problem … If invoice is made, the manager can consult the sale of the day, to consult by Seller the sale, the commission, the manager can consult the article sold, the order of supplier. He must also have the Challenge module: for example, the Seller A must sell the 5 copies of SuperCool model glasses, the manager can consult if all goes well. We can also fix the sales goal of the shop: 10000 € per month and 100000 € per year. There is of course stock management, barcode, inventory, reporting, statistics, promotion, mailing, incident ticket, backup, restoration, maintenance of the database. There are 2 programs: 1 for the optical shop, 1 for Aid's Heraing. 80% of the functions are common in the 2 software, the difference is: The medical data of the patients (telescope and Audio), doctor, the technical data on the purchased products THE SOFTWARE MUST BE COMPLETE SOLUTION OF MANAGEMENT. Regarding the website of Showroom and Mobile App, this is another project. About users: There is only one SuperAdmin, I am the only one who creates the other Admin, and the centers. Admin can: Created all leftovers. But is not allowed to create centers and Admin. Maintenance of the database. + all Admin Support tasks. Admin assistant: Creating articles, barcode, set rates, discounts, sales price, purchase price, creating suppliers, promotions, send mailings, + All secretary tasks. Payments, refund. + All the spots of sellers Secretary: Creation of doctors, patients, tax, appointments, all documents Seller: Creation of patients, appointments, sales documents, quotes. Forbidden to create: RMA, refund, service-after-sale, information regarding payment. Place orders at suppliers. Payment of a subscription. The software is designed for our private use. But it is expected that we rent the software to other shops for € 29.99 per month. The Super Admin must manage the subscription by month or by year. If customers (shops) do not pay, the given database is in read-only mode.