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RAG systems

RAG systems: first they search,then they answer.

A RAG (retrieval-augmented generation) system is an AI assistant that, before answering, searches the configured data sources and builds its answer on the passages it finds, with references to them. It improves relevance and makes answers verifiable, although it does not eliminate every error.

A language model does not know your documents

An LLM answers from what it learned during training: it does not know your procedures, prices or contracts, and it may fill the gaps with plausible but false information. Loading every document into a conversation is impractical and does not respect access rights.

  • Confident answers with no source that can be checked
  • Outdated information, because the model does not know which document has been replaced
  • The risk that a user receives excerpts from documents they have no access to
  • No rule for questions the documents do not answer

Who it is for

  • Companies that want an AI assistant that answers from their own documents, not from general knowledge
  • Teams that need to be able to check where every answer comes from: quality, compliance, legal
  • Companies that have tried a chatbot on their documents and got invented or unsourced answers
  • Technical teams that want to understand and control how the system chooses its information

What a RAG system does, step by step

  • 01

    Preparing the sources

    Documents are split into chunks and indexed by meaning, keeping the date, version and access level.

  • 02

    Finding relevant passages

    For each question, the system looks for the chunks closest in meaning, only from the sources the user is allowed to see.

  • 03

    Answer from the chunks

    The model receives the question and the passages found, and is instructed to answer only on that basis.

  • 04

    Verifiable citations

    The answer points to the document and passage used, so the user can open the source.

  • 05

    Reasoned refusal

    If the passages found do not contain the answer, the system says so instead of making something up.

  • 06

    Reindexing on change

    Modified or withdrawn documents are updated in the index on an agreed schedule.

How it works

A question's journey through a RAG system

The steps marked in yellow are approved by a person.

  • Input
  • Action
  • AI
  • Human in the loop
  • Result
  1. 01

    Input

    The user's question

    Your colleague asks in their own words, in a chat or in an application.

  2. 02

    Action

    Access filtering

    The system identifies the user and limits the search to the sources they are entitled to.

  3. 03

    Action

    Index search

    The chunks most relevant in meaning are found, from current documents.

  4. 04

    AI

    Answer with citations

    The model writes the answer from the chunks or says the information is missing.

  5. 05

    Human in the loop

    Checking the source

    The user opens the citation and confirms the information before relying on it.

  6. 06

    Result

    Answer and feedback

    The answer is used, and the user's rating feeds into the quality analysis.

What components a RAG system has

  • The configured sources: documents, internal pages, resolved tickets, tables
  • Metadata for each document: date, version, department, access level
  • A semantic search index (embeddings), updated regularly
  • Instructions for the model: answer only from the sources, cite them, acknowledge missing information
  • A set of test questions with known correct answers

Possible integrations

  • Google Drive
  • Microsoft SharePoint
  • Confluence
  • Notion
  • PostgreSQL with pgvector
  • Qdrant
  • Elasticsearch
  • PDF and Word files
  • OpenAI API
  • Anthropic API
  • Google Drive
  • Microsoft SharePoint
  • Confluence
  • Notion
  • PostgreSQL with pgvector
  • Qdrant
  • Elasticsearch
  • PDF and Word files
  • OpenAI API
  • Anthropic API

Each integration's compatibility is checked during the analysis phase, for the systems and versions you use.

Control and transparency

What people validate

  • Choosing which sources go into the index and withdrawing outdated ones
  • Access rights, aligned with the permissions in the original systems
  • Answers used for important decisions, checked directly against the source
  • Regular review of answers marked as wrong and of unanswered questions

Limitations and how we handle them

  • RAG reduces the risk of invented answers but does not eliminate it: the model can misinterpret a correct passage
  • If the search returns the wrong chunk, the answer will be wrong, even if it has a citation
  • Scanned documents, complex tables or images may be read incompletely
  • Contradictory information from different sources is not resolved automatically; the system can only flag it
  • Answers are only as current as the last reindexing of the sources

How we evaluate a RAG system's quality

We agree the indicators together before launch and track them afterwards. The values depend on the process, the data and the volume.

Relevance of retrieved chunks
Whether the chunks retrieved for each test question contain the answer — checked by the team.
Faithfulness to sources
Whether the answer says only what is in the chunks, assessed on a sample of real answers.
Citation accuracy
Whether the cited document actually supports the statement, checked manually by spot checks.
Correct refusals
Behaviour on questions the sources do not answer, deliberately included in the test set.
Index freshness
The time between a document being changed and the new version being used in answers.

How we implement a RAG system

  1. 01

    Sources and access

    We agree which sources are included, who is entitled to what and how often the documents change.

  2. 02

    The test set

    We gather real questions with known answers, including questions the documents do not answer.

  3. 03

    Indexing and tuning

    We split and index the documents, then tune the search until the chunks retrieved are relevant.

  4. 04

    Pilot and reindexing

    We launch to a small group, analyse the feedback and set the schedule for updating the sources.

Use cases

These scenarios are conceptual examples showing what can be built. They are not delivered implementations or results achieved for clients.

  • Industrial equipment manufacturer

    Answers from technical data sheets

    Sales engineers ask about specifications and get the answer with the relevant data sheet page cited, which they check before sending it to the customer.

    Conceptual example
  • Insurance broker

    Policy terms

    Advisers ask what a product covers, and the system answers from the terms in force, citing the clause; explaining it to the customer remains the adviser's job.

    Conceptual example
  • Private clinic network

    Internal administrative procedures

    Reception staff find the steps for reimbursements or rescheduling in the approved procedures, without the system having access to patient data.

    Conceptual example

Frequently asked questions

  1. What does RAG mean?

    RAG stands for retrieval-augmented generation, meaning generation supported by search. The system first searches your documents for relevant passages, then the language model writes the answer based on them and shows the source.

  2. How is RAG different from an ordinary chatbot?

    An ordinary chatbot answers from the model's general knowledge. A RAG system searches your sources first and answers on that basis, with a citation. The practical difference: the answer can be checked.

  3. Does RAG eliminate mistakes?

    No. It reduces them and makes them easier to spot. The system may pick the wrong passage or misinterpret a text, which is why we show the sources, test on real questions and recommend human review for important decisions.

  4. What happens when the documents do not contain the answer?

    The system is instructed to say clearly that it did not find the information and, where appropriate, to point the user to someone who can help. These questions are logged, because they show what is missing from the documentation.

  5. Who sees what in the answers?

    The search is filtered by the user's permissions before the model receives any passage. Only the relevant passages reach the model provider, not the whole archive; for sensitive data we also consider privately hosted models, and the processing of personal data is assessed in line with the GDPR.

  6. How is it different from an enterprise knowledge base?

    This page describes the technique: how the system searches and answers. An enterprise knowledge base deals with the surrounding infrastructure: which sources exist, who owns them, how they are updated and how they are governed across the whole company.

  7. How often are the sources updated?

    It depends on the pace of change: on every change for critical documents, daily or weekly for the rest. Withdrawn documents are removed from the index so they are no longer cited.

Can’t find the answer? Write to us and we’ll reply directly.

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