The separation of Project Accounting from Financial Accounting is common in many firms. Finanical Acounting is the domain of the CFO or equivalent and the finance and accounting department, where payments of invoices to customers and from suppliers ae processed.
Project Accounting, sometimes called Job Cost Accounting, is usually the domain of the Project Manager. Where budgets are assigned and records of work peformed and cost of that work reported. But actual money doesn't change hands.
In the Financial Accounting domain, all costs and all income are recorded as transactions on the General Ledger. These transctions are rolled out through accounts to produce a Balance Sheet of the cost versus value in some form. Sometimes that value is revenue. Sometimes, it's business value recorded as intangible asset. Managing of the intangible assets of a firm is the primary role of business leaders. Teh tangible assets are usualy managed in the accounting, by the depaertment with the same name.
I'm making this simple, and likely simple minded for the point that is coming. Who owns the overhead costs that are present in every single business? For larger complex projects here's one framework for doing that, but we'll keep it simple for now.
But before going simple here's a quick looks at FASB 86, the guidance for accouting for the development and use of software. But one quick notion that is missed by many in the agile world not working the arcane processes of public accounting ...
The Agile Alliance is working this issue.
So Back To Project Accounting Processes
Projects spend budget. Businesses spend Funds. If you work on a project, rarely does someone on the business side come to you with an envelope full of money - dead presidents - and say go hire some developers to write code for this project. Those authorizing you to hire people, or buy materials, do so with a Purchase Order of some sort (we have PCARDS that skip all the paper work), or some authorization from HR to hire. The employee or contractor then charges to a charge number or Employee Number to capture their expenses (labor or material).
That expense is then wrapped with fringe, overhead, and other indirects and recorded on the books as the Fully Burdened cost to the project.
Someone Has to Pay
No matter where you work in the organization, the all in cost for the project has to be paid. This includes your direct labor. What you get in your pay check, those fringe benefits - health insurance, matching 401(k), AMC movie passes, spot awards. Your firm has to pay. If you're a 1099 supplier, then it's you that has to pay. As a 1099, if you're not billing your customer for all that overhead than those costs are reducing your revenue. Same for a firm.
So if you're not concerned about overhead, don't manage the project knowing the overhead. Not a problem in principle. In practice though someone does, and if they care, you may want to care as well. If not, then you're likley working as labor on the project. That's in NO way a problem. We're all labor in some form to some one. But when it comes to managing projects and managing the business that projects use or produce, these indirect costs can make or break the project and or the business. Knowing about them, managing in their presence is simply the responsible thing to do. You know likey knowing what your project will cost when it's done.
Here's some background that have served me well over time as a Program Planning and Control manager.