What an ERP does
Enterprise resource planning (ERP) software runs the core of the business: the general ledger, payables and receivables, purchasing, inventory, fixed assets and financial reporting, and often people and payroll. It is the system of record for money.
What a PSA does
Professional services automation (PSA) software runs client work: projects, resource planning, timesheets, expenses and billing. It is the system of record for the work and the people doing it. See what is PSA software?
| ERP | PSA | |
|---|---|---|
| Primary remit | Running the business: the books, purchasing and people | Running client work: projects, staffing and time |
| Main records | Accounts, journals, suppliers and employees | Projects, tasks, timesheets and expenses |
| Typical areas | Finance, purchasing, inventory and HR | Project management, resource planning, timesheets and billing |
Where they overlap
Both care about time, cost and revenue. The PSA knows which hours were worked on which project; the ERP needs those hours to recognize revenue, invoice clients and pay people. Purchases charged to projects start in the ERP but belong in the PSA’s project margin.
The problem with running two systems
- Integrations to build, pay for and maintain
- Clients, projects and people set up twice
- Month-end reconciliation between project numbers and the ledger
- Reports that disagree because they come from different data
One record instead of two systems
An alternative is a platform where the PSA and the ERP share the same data: the project that holds the timesheets is the same project the ledger reports on. That is how Perspectiv is built.
Which do you need first?
If your pain is staffing, timesheets and project visibility, start with PSA. If it is accounting, purchasing and multi-entity reporting, start with ERP. If it is both, choose a platform that does both, so you do not have to connect them later.
Start with PSA if your pain is…
Staffing, timesheets and seeing how projects are doing.
Start with ERP if your pain is…
Accounting, purchasing and running more than one legal entity.
How Perspectiv helps
Labels show what opens first in the private beta (Q2 2027), what is being built now, and what is on the roadmap.
- Project managementComing soon
Projects, programs and portfolios, with budgets, change orders, WIP, profitability and forecasts.
- Time & expenseComing soon
Timesheets, timers and expenses against the work, approved and ready to invoice.
- General ledger & accountingPlanned
Chart of accounts, journals, multi-entity accounting, intercompany, revenue recognition and period close.
- PurchasingPlanned
Requisitions, purchase orders, receiving, vendor invoices and a vendor portal.
Questions
Can an ERP replace a PSA?
Some ERPs include project modules, but many are built around products and inventory rather than people and time. Check how they handle resource planning, timesheets and project billing.
Can a PSA replace an ERP?
Usually not on its own: most PSAs rely on a separate accounting system for the ledger, payables and financial reporting.