An approval workflow is a set of rules that sends each request to a named person, gives them a deadline, records their decision and says what happens when they do not answer. Most approval problems are not software problems. A purchase sits for weeks because the approver was on leave, or an auditor asks who approved a payment and the answer is in a forwarded email.
Automating the workflow approval process removes the chasing and the missing record. It does not fix an unclear rule. If two managers would give different answers about who signs off on a software renewal, an automated approval workflow only routes that confusion faster. So the work starts with the rule, then the routing, then the tool.
Benian Technologies is an AI implementation partner. We build approval flows in accounts the client owns, usually n8n, connected to the email, Slack or Teams the team already uses. Purchase orders are the worked example below, because that is where most approval searches start.
Where approvals cost money before any tool is chosen
No deadline and no escalation
An approval with no timer can wait forever. The cost shows up later as a rush order or a lapsed vendor quote.
Approvals that happen after the fact
Staff order first and ask for sign off later because the official route is slower than the work. The approval controls nothing.
No record an auditor would accept
A thumbs up in a chat thread does not show the amount, the version of the request or when the decision was made.
Out of office breaks the chain
The one approver for a category goes on vacation with no named delegate, so requests stack up or someone approves without authority.
What a good approval workflow has: owner, rule, deadline, record
Every approval step needs four things written down before anything is built. The owner is a named person, never a group. The rule says which requests reach that owner, usually by amount, category or department. The deadline says how long the owner has before the request escalates. The record captures who decided, what they saw and when.
Miss one and the automation approval process fails in a predictable way. No owner means requests stall. No rule means everything goes to the most senior person, who becomes the bottleneck. No deadline means silence is treated as a decision. No record means the approval cannot be proven later, which matters most on spending, contracts and refunds.
Designing an approval matrix by amount and category
An approval matrix is a table your finance or operations lead signs off before the build. Rows are request types, such as software, contractors, equipment and refunds. Columns are amount bands your business sets. Each cell names who approves, whether one or two approvals are required, and whether steps run in sequence or in parallel.
Keep it short. A matrix with dozens of cells usually means the policy is not decided yet, and automating it locks in the confusion. Anything outside the matrix routes to one named person who decides and, if the case repeats, adds a row.
- A requester never approves their own purchase order.
- Decide whether a price change after approval sends the request back through the matrix.
- Keep the matrix in a sheet or table the workflow reads, so policy changes do not need a developer.
A worked example: purchase order approval end to end
A purchase order approval workflow starts with a request form. The requester enters vendor, items, amount, budget line and reason, and attaches the quote. The workflow refuses incomplete requests before any approver sees them, because an approver who has to ask for the missing quote slows every cycle.
The workflow reads the matrix, finds the approver for that category and amount, and sends a summary with the quote and two buttons. In a higher band, the second approver gets the request only after the first approves. After the last approval, the PO workflow creates the purchase order in the accounting or purchasing system and tells the requester.
When the invoice arrives, it is matched to the approved order. A mismatch on amount or quantity goes back to a person instead of into payment.
Approving from Slack, Teams or email without losing the audit trail
People approve faster where they already work, so approvals from Slack, Microsoft Teams or an email button are worth building. The risk is a decision that lives only in a chat message. The button is a front end, not the record. On approve, the workflow writes request id, approver, the exact amount and version shown, decision, comment and timestamp to a log the business owns.
Two checks matter. The button confirms the person clicking is the assigned approver, not anyone in the channel. And if the request changes after the message went out, the old button stops working and a new request is sent, so nobody approves an amount that is no longer the amount being paid.
Escalation, delegation and out of office handling
Every step gets a timer. When it runs out, the workflow sends one reminder, then escalates to a named backup or the approver's manager, stating how long the request has waited.
Delegation is a policy question first: who may approve for whom, for which categories and up to which band. When an approver sets a delegate before leave, requests route there and the record shows the approval was delegated. Never fall back to whoever is available, which is how people approve spending they have no authority over.
Power Automate approval workflows compared with n8n
If your company runs on Microsoft 365, a Power Automate approval workflow is a reasonable place to start. Approvals are built in, with responses in Outlook and the Teams Approvals app, and options such as first to respond or everyone must approve. Multi level approvals chain steps in sequence. Microsoft licenses it per user or per flow, and some connectors need a higher license, so check your current licensing first.
Benian builds in n8n by default. n8n can be self hosted or run in its own cloud, and it can pause a workflow until a person responds through a webhook, Slack, email or Teams. It suits approvals that cross several non Microsoft tools, or firms that want workflow files and logs in an account they control. Neither tool decides your matrix.
Where AI can prepare an approval and where it must not decide
An AI agent is useful before the approver looks. It can read the quote, extract vendor, amount and line items, flag a mismatch with what the requester typed and summarize a long contract. That removes reading work, not the decision.
A named person approves anything financial or irreversible: purchases, payments, refunds, contract terms, bank detail changes and system access. AI can auto approve only where written policy already says no human review is needed, such as a repeat order for the same item from the same vendor within an agreed band, and the record names the rule that approved it.
Common failure points and how to test them before launch
Before launch, replay a set of real past requests and compare each route with what should have happened. Then test the cases that break approval systems in practice.
- An amount exactly on a band boundary.
- A requester who is also an approver.
- An approver who leaves or changes role.
- A request edited after the first approval.
- The messaging tool or accounting system down when a decision arrives.
- A rejection with no comment, and what the requester is told next.
Power Automate approvals compared with an n8n approval workflow
| Question | Power Automate | n8n |
|---|---|---|
| Best fit | Teams that work mainly in Microsoft 365 | Teams whose tools span several vendors |
| Where people approve | Outlook, Teams and the Approvals app | Slack, Teams, email or a simple web page you design |
| Multi level approvals | Chained approval steps in sequence | Chained or parallel steps built in the workflow |
| How cost grows | Microsoft licensing per user or per flow | Per execution on n8n cloud, or your server costs if self hosted |
| Setup effort for approval screens | Lower, built in | Higher, built to your design |