Develop a conceptual data model for the following scenario:

The data model should consist of the usual 5 components: E-R diagram, Entity Types (including entity type identifiers), assumptions, additional constraints, and limitations.

It is desired to develop a company database, a company that performs projects for clients.

A company consists of several departments. For each department, it is required to keep the following information: department number, department name, address, email address and telephone number. Each department has one or more employees and may or may not conduct projects. Each department has one department head employee. A department may have zero, one or more deals with clients. The maximum number of employees can work in a department is 15.

The following information of employees are required to be kept: employee number, employee name, hire-date, number of working hours, salary, address, email address and mobile phone number. An employee is worked in one department. An employee can work in one or many projects. Every employee may or may not be a head of department. An employee may or may not be a supervisor of the project.

Every project is conducted by one department. The following information of project needs to be kept: project number, project name, description, address, cost, start date and end date. Every project required one or more employees, but not more than 10, to work in it. A project can have one or more tasks to be done. Every project has one supervisor employee. A project can be done for one client.

A client is dealt with one department. The information of every client is required to be kept: client number, client name, address, email address and mobile phone number. Each client can request for one or more projects.

A task can be used in one or more projects. It is necessary to keep the information of each task: task number, task name, task type, description, start date and end date. Each task uses one or more tools to be performed.

A tool can be used in one or more tasks. For each tool, the information of tool needs to be kept: tool number, tool name and description.

Note: you should expect about 9 entity types, 12 relationship types, 40 attributes, 8 additional constraints, 4 assumptions and 3 limitations in the CDM for this application.

This question was answered before but the answer was wrong. Please I need the correct answer.