There are scenarios in construction where there are fixed parameters to work with, in which you can apply a fixed contract to the work you get. With everything predetermined and to play out as expected, this shall be a good way to assure your company of a decent profit. But in scenarios where not much is certain, it could spell huge losses once you sign a contract. This is where time and material contracts come into play.
A time and material contract shall take into consideration certain factors. There shall be a fixed hourly rate for all labor provided in this job, which cover all the personnel and management involved. There will also be a markup on the materials used, which should be a reasonable percentage. Other factors such as limits on the cost of the material to be incurred can be added, to safeguard the financial side of the contract. When invoicing for the work done, you will need to have all the documentation of everything that happened at the work site. From the hours of labor, materials bought and used, all payment to subcontractors, and such details, it shall serve as evidence for the figures quoted on the invoice.
You shall use this type of contract in several scenarios. Where it is not known how the project will pan out, it will be wise to use this style. Sometimes even the client is not sure how the work will turn out, or what they want. You cannot risk using a fixed type of contract there. The same applies where the timeline for the project is not definite. Click on this link for more details abot time and material contract: https://rhumbix.com/the-7-best-project-management-apps-for-the-construction-industry.
You can also apply it where you both agree it is best. There are scenarios where a fixed contract may end up costing the client more than they feel is right, even if it is a definite figure. You can then introduce the idea of a time and material contract, to keep everything well accounted for and the cots justified.
If the project shall take a long term approach and have plenty of moving parts, then this shall also work out well. Changes shall be accounted for better in a time and material contract due to the factoring in of those changes in the costing. Such flexibility is not available in a fixed contract, which would spell a loss for your business, or overpayment on the client’s side, depending on the agreed upon amount.
You also need to use it more when you are new and still learning the true nature of the industry. There will be so much you need to understand before you can successfully quote a fixed contract figure. Your estimations will not have matured yet to a level where you can be sure of a profit. Learn more about projects here: https://en.wikipedia.org/wiki/Project_management.