Job-Order Costing and ERP Systems

The document flow in job-order costing is fundamentally a data integration problem—which is exactly what ERP systems solve.

What needs to talk to what

SystemData It HoldsWhat It Needs From Others
Sales/CRMCustomer info, orders, pricingJob costs (for quoting), delivery status
InventoryStock levels, locationsRequisitions, reorder triggers
PurchasingSupplier info, POs, invoicesStock levels, budgets
TimekeepingLabour hours by employeeJob numbers, wage rates
ProductionJob status, materials usedAll of the above
AccountingPOHR, journal entries, statementsActuals from all systems
EstimatingBudgeted costs by jobActuals for variance analysis

Without integration

ProblemConsequence
Manual data entry across systemsErrors, delays, reconciliation nightmares
Batch updates (end of day/week)Stale information for decisions
No single source of truthConflicting reports from different departments
Can’t trace costs in real timeJob profitability unknown until after completion

What ERP does

ERP = one integrated system that handles the document flows Chapter 5 describes manually

When a materials requisition is entered, it simultaneously:

  • Updates inventory quantities
  • Posts to the job cost sheet
  • Creates the journal entry (Dr. WIP / Cr. Raw Materials)
  • Updates job status visible to production

Connection to Chapter 5 concepts

Chapter 5 ConceptHow ERP Handles It
Materials requisition formDigital form triggers inventory + accounting entries
Time ticketTime tracking linked to job numbers and payroll
Job cost sheetReal-time accumulation from all cost inputs
POHR applicationAutomatic as labour/machine hours are logged
Under/overapplied varianceCalculated continuously; visible before year-end

Why this matters

The manual document flow (sales order → production order → requisition → time ticket → job cost sheet) reveals what information needs to flow where. Understanding the flow conceptually helps you:

  1. Recognize what ERP systems are actually doing
  2. Troubleshoot when systems don’t integrate properly
  3. Design workarounds when full integration isn’t available
  4. Ask better questions during system selection or implementation