I need help with figuring out the relationships between Customer, Company, Consultation, Quote and Installation for creating the ER Diagram for the following information:

Would it be Design Consultation creates Quote, Quote can have Customer, Quote is assigned to Installer?

Customer. It all started with the customer. Key information had to be recorded for every customer or potential customer, such as name, email address, and phone number. While the contacts street address was often recorded, it was not necessarily required. Also, referrals were an important source of fresh sales, so it was important to keep track of situations where an existing customer referred a potential new customer to Company C1.

Company. C1 worked with individual customers, but also with company customers (e.g., builders, interior designers, and other closet companies). Individual customers were not affiliated with any company, but for those customers who did work for a company, it was important to keep track of their company-specific information, such as company name, email address, phone number, and website address, as well as the type of account (builder, interior designer, etc.). Therefore, a given company could employ many customers, whereas a given customer could be employed by only a single companyor no company at all.

Consultation. When a customer approached C1, a design consultation was scheduled for a particular date and time. Consultations could take place at a location different from the contacts address, so it was necessary to record this information. It was possible for a customer to have multiple consultations, if needed, but each consultation involved only one customer. Furthermore, each consultation involved only one designer, but a designer was involved in many different consultations.

Quote. After a successful consultation, a quote was generated and sent to the customer. A customer could have many quotes, but each quote was always specific to one customer. The quote contained lines that described each unit being purchased; for example, unit name (e.g., Shoe Rack 73), price ($189.99), quantity (1), and notes (e.g., desired color, and installation location). A quote usually included multiple units (lines), and a given unit could appear on many different quotes. A quote also contained the total amount, the taxes, an optional discount rate for the customer, and an optional note. Additionally, it was important to track whether a quote was accepted or not.

Installation. Once a quote was accepted, an installation was scheduled. Some jobs required multiple installations on different days, but each installation was always related to one quote. In addition to the installation's date and time, the installation's address needed to be collected. This information could differ from the contacts address (e.g., when the contact was a builder). Only one installer was normally assigned to each installation, although multiple installers could be involved on larger jobs. Therefore, it was important to track which installers were responsible for each installation, including their names and contact information. Over time, the same installer could be involved on many different installations.