What a workflow audit gives you

Workflow

Supplier invoices, from arrival in the AP inbox to an approved vendor bill in NetSuite

In scope

PO and non-PO supplier invoices, credit notes, approvals and exceptions

Out of scope

Payment runs, employee expenses, accounts receivable

Period

Weeks 1–2, with three months of inbox and NetSuite history

Method

Six interviews (AP lead, two AP clerks, controller, two buyers), 60 invoices timed end to end, and a prototype run on 400 past invoices

Findings

1. 1

   About 52% of invoices can run from inbox to approval request without an AP clerk touching them. 31% need a short review of highlighted fields. 17% stay with people as exceptions.

2. 2

   In the base case, AP and approver time falls from about 368 to about 95 hours a month, a gross saving of about $12,200 a month before running costs.

3. 3

   The largest single cause of exceptions is a process gap: about 1 in 10 PO invoices arrives before the item receipt is recorded. Fixing that is cheaper than automating around it.

4. 4

   Duplicate checks today search by invoice number only. Three duplicate payments in the last 12 months got through this way. Stronger checks are part of the build.

Fictional sample data

invoices / month

2,400

78% with a PO, 22% without

minutes per invoice

9.2

Average of 60 timed invoices, all steps

hours / month

368

AP team 344 h, approvers 24 h

exception rate

23%

Invoices needing a person to resolve something

days, median cycle time

6.5

Arrival to approval, business days; 90th percentile 15

rework rate

1.8%

Bills corrected, voided or re-entered after posting

Fictional sample data

• About 640 active suppliers. The top 50 send 61% of invoices.
• Four AP clerks and an AP lead. Invoice work takes about 60% of the clerks' time.
• Late-payment fees average about $1,100 a month. Tracked separately and not counted in the estimate.
• Three duplicate payments in the last 12 months, all recovered after supplier statements were reconciled.

• Straight-through

  52%1,248 / month

  Matched, validated and sent for approval with no AP touch.

• Assisted

  31%744 / month

  A clerk checks the highlighted fields, about 1.5 minutes each.

• Manual

  17%408 / month

  Exceptions resolved by a person, about 6 minutes each with the context prepared.

Fictional sample data

• Person

  Approving invoices

  Every approval follows the delegation of authority matrix. The system never approves an invoice.

• Person

  Bank-detail changes

  A named controller verifies any change with the supplier through a known contact, outside the email thread.

• Person

  Price and quantity disputes

  Buyers resolve variances with suppliers. The system shows ordered, received and invoiced figures side by side.

• Person

  New suppliers

  Procurement onboards them. The system passes on the supplier details it extracted.

• Person

  Releasing payments

  The payment run, and who can release it, stays as it is today.

• Person

  Changing the rules

  Tolerances, thresholds and the approval matrix are changed only by the controller, and every change is logged.

• Duplicate payment

  Duplicate checks on normalized invoice number, on supplier, amount and date within 30 days, and on the file itself. Posting is idempotent, so a retry cannot create a second bill.

  Owner: AP lead

• Bank-detail change fraud

  Remittance details on every invoice are compared with the vendor master. A mismatch holds the invoice and alerts the named controller. The system can never edit vendor records.

  Owner: Controller

• Segregation of duties

  The person who raised a PO cannot approve the invoice against it. Nobody can approve payment to a supplier whose details they changed. Enforced in rules and checked in the test set.

  Owner: Controller

• Wrong value posted without review

  Review thresholds set from errors measured on the test set. Critical fields are always validated against the PO and vendor master. 2% of auto-processed invoices are sampled each week.

  Owner: AP lead

• Instructions hidden in inbound email

  Email and attachments are treated as untrusted input. The model returns structured fields only, and every action is limited by the integration role, outside the model.

  Owner: Scenox

• Accuracy drifts as suppliers change layouts

  The test set is re-run monthly and after every change. An alert fires when the review rate or error rate rises above the agreed level.

  Owner: Scenox

• System unavailable

  Invoices queue in the inbox and nothing is lost. AP can process by hand in the meantime, exactly as today.

  Owner: Scenox, AP lead

Fictional sample data

1. 01Rules

   Intake

   Shared inbox and portal exports

2. 02Model

   Read

   Classify, split, extract fields

3. 03Rules

   Check

   Validate, de-duplicate, match

4. 04Person

   Approve

   Request and decision in Slack

5. 05Rules

   Post

   Vendor bill in NetSuite

Anything that fails a check goes to the exception queue with its reason, then rejoins the flow once a person resolves it. Every step is written to the audit log.

Integrations and access

• AP shared inbox

  Microsoft 365

  Reads new mail and attachments; files processed mail into a folder.

  Access

  AP mailbox only, through an application access policy

  Cannot

  Send email or open other mailboxes

• NetSuite

  SuiteTalk REST

  Reads vendors, POs and item receipts; creates vendor bills as pending approval, with the PDF attached; records each approver’s decision.

  Access

  Custom integration role, token-based authentication

  Cannot

  Edit vendor records or bank details, create payments, approve bills

• Slack

  Bot user

  Sends approval requests and reminders to approvers; posts exception alerts to #ap-exceptions.

  Access

  Direct messages to approvers and two channels

  Cannot

  Read other channels

• Operator console

  Scenox

  Exception queue, audit log of every step, weekly report against the metrics in section 07.

  Access

  Northwind single sign-on, AP and finance roles

  Cannot

  Change rules without a logged controller approval

1. Weeks 1–2

   Audit

   • Interviews, timing and data pull
   • Prototype on 400 past invoices
   • This report

   Output: Signed-off report and fixed price

2. Weeks 2–3

   Design

   • NetSuite sandbox and inbox access
   • Approval matrix encoded and reviewed
   • Test set labeled by AP

   Output: System design and test plan

3. Weeks 3–5

   Build

   • Intake, extraction and validation
   • Matching, coding and Slack approvals
   • Scored on the test set after each change

   Output: Test-set results against section 07

4. Weeks 5–6

   Shadow run

   • All live invoices processed in parallel
   • Daily comparison with AP’s own work
   • Go or no-go review with the controller

   Output: Pilot results and sign-off

5. Weeks 6–8

   First go-live

   • PO invoices from the top 50 suppliers
   • Weekly sample review of processed invoices

   Output: Live on 61% of volume

6. Weeks 8–10

   Widen

   • Remaining PO invoices, then non-PO
   • Review thresholds lowered only where the data supports it

   Output: Full scope in production

Inputs

Monthly volume

2,400 invoices

Touch time today

9.2 min per invoice

Loaded hourly cost

$42

Rework rate today

1.8%

Cost per rework

$30

Approver time

24 h / month, unchanged

Fictional sample data

Build and running costs

• Build

  $X

  Fixed price quoted here in your report. Covers design, build, pilot and staged rollout.

• Running

  $Y / month

  Quoted here in your report. Model usage, hosting, monitoring and maintenance.

Left blank in this example. Your report states both as fixed figures.

Result, base case

Gross monthly saving

$12,169

$16,746 − $4,577

Net monthly saving

$12,169 − $Y

After running cost

First-year gross saving

$135,076

40% in month 1, 70% in month 2, full from month 3

Hours freed

≈ 273 h / month

368 h − 95.4 h

Payback month  = first month where
                 cumulative gross saving − (months × $Y) ≥ $X

First-year ROI = ($135,076 − $X − 12 × $Y) ÷ ($X + 12 × $Y)

Pays back in year one if  $X + 12 × $Y ≤ $135,076

Low, base and high cases

Fictional sample data

• Freed hours are counted as cash only to the extent they change spending. Northwind plans a fifth AP hire next year as volume grows; avoiding that hire is the cash case. The rest is capacity.
• Late-fee reductions, early-payment discounts and shorter cycle time are real but tracked separately, outside these numbers.
• The split comes from the prototype run on 400 past invoices. The pilot replaces it with measured live figures before full rollout.

1. Q1

   Will Northwind allow fully matched PO invoices under a set amount to be approved by a written rule?

   Not assumed in the estimate. If yes, approver time falls further.

   Owner: Controller

2. Q2

   Who is the named controller for bank-detail verification, and who is the backup?

   Required before go-live.

   Owner: Controller

3. Q3

   Can buyers record item receipts within two business days of delivery?

   This is the largest exception type and a process fix, not an automation fix.

   Owner: Operations director

4. Q4

   Is a price tolerance of 2% or $50, whichever is lower, acceptable to procurement?

   Sets how many invoices match without a buyer.

   Owner: Procurement

5. Q5

   Which of the three supplier portals can send invoices by email or API?

   Decides whether portal invoices are in the first go-live.

   Owner: AP lead

6. Q6

   Is the planned fifth AP hire still in next year’s budget?

   Decides how much of the saving is cash.

   Owner: CFO

7. Q7

   How long must invoice images and logs be kept?

   Sets retention in the build.

   Owner: Controller