System interrelationships: Across typical businesses, accounts receivable systems are least closely interrelated with which other functional system?

Introduction / Context:
Accounts receivable (AR) tracks amounts owed by customers, integrating with order-to-cash processes. Understanding which systems are most and least connected helps in designing interfaces and controls for data consistency and reconciliation.

Given Data / Assumptions:

• AR interfaces with sales orders, invoicing, collections, and general ledger.
• Cost accounting summarizes production and overheads but also reconciles revenue and cost flows.
• Payroll administers employee compensation and is largely separate from customer receivables.

Concept / Approach:
AR is tightly linked to sales order processing (orders → invoices → receivables) and posts to the general ledger, feeding management and cost accounting reports. Purchasing is part of procure-to-pay and connects more to accounts payable. Payroll pertains to employee payments and benefits, with minimal direct linkage to customer receivables beyond shared GL structures.

Step-by-Step Solution:

Verification / Alternative check:
ERP architectures (order-to-cash vs procure-to-pay vs hire-to-retire) separate AR from payroll modules, confirming loose coupling.

Why Other Options Are Wrong:

• Cost accounting: relies on revenue and margin data that tie back to AR invoicing.
• Sales order: directly feeds AR with billable transactions.
• Purchasing: although less related than sales, can connect via customer returns/credits; still more relevant than payroll to AR operations.

Common Pitfalls:
Assuming everything in finance is tightly linked; functional cycles in ERP are intentionally modular with defined interfaces.

Final Answer:
payroll system