EDIFACT message guide · Projects and construction

CONAPW Advice on pending works

The UN/EDIFACT message a contractor uses to advise authorities and utility networks of planned works and to request plans of their services.

Sent by
Contractor
Received by
Public authorities and utility network operators
Standard
UN/EDIFACT · Batch message
X12 equivalent
620 Excavation Communication

What is the EDIFACT CONAPW message?

CONAPW is the UN/EDIFACT advice on pending works message. The directory describes it as enabling a contractor that intends to start works to advise public authorities and water, gas, telephone and electricity distributors of its intention, and to ask them to send back plans or information about their networks in the area.

Knowing where cables and pipes run before digging prevents damage to networks and injuries to workers. Network operators reply with CONRPW, giving details of their services in the work area.

How the EDIFACT CONAPW message worksDiagram of the UN/EDIFACT CONAPW Advice on pending works message. Contractor sends it to public authorities and utility network operators. It usually starts the exchange. It is usually followed by CONRPW. Inside the UNB and UNH envelopes, the directory D.21A requires, in the start of message: BGM (Beginning of message), RFF (Reference) and DTM (Date/time/period), body and segment groups: the required SG1 loop with NAD (Name and address) and end of message: LOC (Place/location identification) and FTX (Free text). 1 conditional segment groups are listed by their trigger segment.How the EDIFACT CONAPW message worksAdvice on pending works: who sends it, where it fits and what the directory marks mandatory1 WHERE IT FITSUSUALLY FOLLOWSStarts the exchangeCONAPWSENDERContractorRECEIVERPublic authorities andutility networkoperatorsCONTRL syntax report back, if agreedUSUALLY FOLLOWED BYCONRPWResponse of pendingworks2 WHAT DIRECTORY D.21A REQUIRESInterchange: sender and recipient IDsUNB … UNZMessage CONAPWUNH … UNTSTART OF MESSAGEBGMBeginning of messageRFFReferenceDTMDate/time/periodBODY AND SEGMENT GROUPSMandatory group SG1 · repeats upto 3NADName and address+ 1 conditional group, starting with:CTAEND OF MESSAGELOCPlace/location identificationFTXFree textBlue box: mandatory segment group. Conditional groups are listed by the trigger segment that starts them; a group is sent only when its data applies.Conditional segments outside groups are not drawn.Structure: mandatory segments and groups in the UN/EDIFACT directory D.21A listing for CONAPW. Your trading partner's implementation guide adds itsown requirements.
How the EDIFACT CONAPW message worksDiagram of the UN/EDIFACT CONAPW Advice on pending works message. Contractor sends it to public authorities and utility network operators. It usually starts the exchange. It is usually followed by CONRPW. Inside the UNB and UNH envelopes, the directory D.21A requires, in the start of message: BGM (Beginning of message), RFF (Reference) and DTM (Date/time/period), body and segment groups: the required SG1 loop with NAD (Name and address) and end of message: LOC (Place/location identification) and FTX (Free text). 1 conditional segment groups are listed by their trigger segment.How the EDIFACT CONAPWmessage worksAdvice on pending works: who sends it, where itfits and what the directory marks mandatory1 WHERE IT FITSUSUALLY FOLLOWSStarts the exchangeCONAPWSENDERContractorRECEIVERPublicauthorities andutility networkoperatorsCONTRL syntax report back, if agreedUSUALLY FOLLOWED BYCONRPWResponse of pending works2 WHAT DIRECTORY D.21A REQUIRESInterchange: sender and recipient IDs(UNB … UNZ)Message CONAPW (UNH … UNT)START OF MESSAGEBGMBeginning of messageRFFReferenceDTMDate/time/periodBODY AND SEGMENT GROUPSMandatory group SG1 · repeats upto 3NADName and address+ 1 conditional group, starting with:CTAEND OF MESSAGELOCPlace/location identificationFTXFree textBlue box: mandatory segment group. Conditionalgroups are listed by the trigger segment thatstarts them; a group is sent only when its dataapplies. Conditional segments outside groups arenot drawn.Structure: mandatory segments and groups in theUN/EDIFACT directory D.21A listing for CONAPW.Your trading partner's implementation guide adds itsown requirements.

How to read this diagram: the top row shows who sends CONAPW, to whom, and which messages usually come before and after it. The lower part shows what the directory D.21A itself requires: the envelopes around CONAPW and the segments and segment groups it marks mandatory. Conditional groups are listed by their trigger segment rather than drawn in full. This is the directory's minimum, not a trading partner's requirement: a message implementation guide, such as an industry subset or a partner’s own guide, usually makes some conditional groups mandatory, restricts the codes and may use an older directory.

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When it is used

  • Notifying utilities before excavation
  • Requesting plans of underground networks
  • Informing authorities of planned roadworks

Where it fits in the message flow

This message CONAPW Advice on pending works
Usually followed by CONRPW Response of pending works

Structure

Mandatory segments in CONAPW (directory D.21A)

In UN/EDIFACT directory D.21A, the CONAPW message has 13 segment positions arranged in 2 segment groups. These are the segments and segment groups marked mandatory at message level, in order; a mandatory group is shown with the segment that starts it. Segments inside conditional groups are needed only when the group is used. This is the directory’s requirement, not your trading partner’s: each partner’s message implementation guide names the directory it uses, often an older one such as D.96A or D.01B where the structure can differ, makes some conditional segments mandatory and restricts the codes.

  • UNH
  • BGM
  • RFF
  • DTM
  • SG1 (NAD)
  • LOC
  • FTX
  • UNT

Practical example

CONAPW in practice

A contractor plans to excavate a trench along a city street for fiber cables. Two weeks before starting, it sends a CONAPW to the city and the gas, water, electricity and telecom operators with the location, dates and type of works. Each operator replies with a CONRPW showing its networks in the area.

Implementation

Implementation considerations for CONAPW

  • Notify all network operators in the area within legal deadlines.
  • Describe the work location precisely, ideally with coordinates.
  • Wait for responses before starting excavation.
  • Follow any national one-call or notification system.

Related messages

Related projects and construction messages

All 14 projects and construction messages

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