Each customized work that you are going to take up needs to be created as separate project and followed up with its tasks and finally it can be billed or non-billed.  It helps to control over the tasks and activities. The Project helps to record the start and end date of that project. The Project members also needs to be assigned.  So you can assign the tasks as per the member you selected for the project. 

Let's see whats possible with Project management based on its types.   As of now, Project comes with 3 types of billing.   

We can also call it as one time billing.  This project can be billed only once.  Like once upon the completion of the project and the progress of 100% helps you to bill the project only once. The Project Cost will be inputted during the time of Project creation.  Once you billed the project you can't edit the price again. 

Hour based billing will be used most of the service providers. like one custom service. and it cant be estimated a fixed price for it. We can use the Project hour based billing. With that you can fix the price of hour. With that counted hours will be billed at the time of project invoice.  Inorder to bill this project. the project status should be completed and also the process should be 100%. 

This is most commonly used in our clients. They bill it based the tasks and its billing cost per hour. This project type also helps us to bill the project multiple times. and you can invoice it when the tasks are completed and its also billable with its task hours.  You can create as many as tasks, only it helps to bill the tasks which are billable and the status of completed.  No mater the project has been completed or non completed. This helps you to bill when you have minimum of one completed task with billable cost. 

These are all the types of Project Billing.  And ofcourse Project type  has 3 types. Like