What Is Human-in-the-Loop (HITL)?
Also known as: HITL, human approval, human in the loop AI
Definition
Human-in-the-loop (HITL) is a design where an AI system proposes an action, such as creating a purchase order, and a person reviews and approves it before it executes. It keeps accountability with people while automating the preparation work.
Human-in-the-Loop (HITL) Explained
AI agents are good at gathering data, drafting and recommending, and unreliable at being right every time. In an ERP, a wrong action can post a journal, release a job or commit a purchase. HITL places an approval step between the agent's proposal and the write, so mistakes are caught before they become transactions.
A typical pattern is read freely, write by approval. The agent can query inventory, demand and supplier data without a gate. When it wants to change something, it creates a draft: a requisition in your ERP's own approval workflow, a proposed reschedule with before and after dates, or a prepared journal entry. A named person sees what will change and why, then approves, edits or rejects.
Approval gates should match risk. Low-value, reversible actions such as adding a note can be automatic with logging. Financial postings, supplier commitments, quality dispositions and anything touching regulated records need explicit sign-off, often by someone with the matching ERP role.
Good HITL design avoids approval fatigue. If people click approve on hundreds of items without reading, the control is empty. Batch similar items, show the evidence and the diff, and track rejection rates so you know where the agent needs improvement.
Why It Matters
- Keeps a named human accountable for changes, which auditors and SOX or quality systems expect.
- Limits the damage from model errors and prompt injection.
- Lets teams adopt AI in stages: suggest first, then automate the actions with a proven low error rate.
- Builds trust, which decides whether people actually use the system.
In Practice
An agent reviews MRP action messages each morning and finds 14 purchase orders to reschedule. It writes a proposal for each with the old date, new date, the demand driving it and the supplier's stated lead time. The buyer approves 11, edits 2 dates and rejects 1. Only approved changes are posted through the ERP's API under the buyer's user, and all 14 decisions are logged.
Frequently Asked Questions
Does human-in-the-loop defeat the point of automation?
No. The agent does the slow part: finding, comparing and drafting. The person only decides, which is usually seconds per item instead of minutes.
What should always need approval?
Financial postings, supplier commitments, quality dispositions, changes to master data and anything touching regulated records. Start strict and relax only with evidence.
Which user should the action run as?
The approving person, so ERP permissions and audit trails reflect who authorised it, not a shared service account.
How do I avoid rubber-stamping?
Show the evidence and the exact change, batch similar items sensibly, sample-check approvals, and review rejection and override rates regularly.
Related Terms
AI Agent
An AI agent is a system that wraps a language model with tools, memory, and a goal so it can plan a sequence of steps, call external systems, observe the results, and iterate until the objective is met or a limit is reached.
AI Guardrails
AI guardrails are the technical and policy controls placed around an AI system that constrain what it may receive as input, what it may produce as output, and what actions it is permitted to take, independent of what the model itself decides.
Prompt Injection
Prompt injection is an attack in which instructions are hidden inside content an AI system reads, causing the model to follow the attacker's directions instead of the operator's, because a language model cannot reliably separate instructions from data.
SOX (Sarbanes-Oxley) Compliance
SOX compliance is a US public company's obligation under the Sarbanes-Oxley Act of 2002 to establish, document, test, and certify internal control over financial reporting, including the IT general controls and segregation of duties in the systems that produce financial data.
MRP Action Messages
MRP action messages are exception prompts generated by the planning run, telling planners to release, reschedule in, reschedule out, change quantity or cancel existing orders so supply matches current demand.
Working with Human-in-the-Loop (HITL) in a live environment? Our engineers do this every day - and our AI agents automate most of it.