# Initial installation of a mME in an existing metering location — GMSB view The gMSB informs the LF of the intent and the planned time period of the first device replacement with a mME. The device replacement will take place within the planned installation window of no more than twelve months. Delimitation: the process does not apply in the case that - the initial installation is initiated at the customer's request (not due to roll-out) or - there is a technically required replacement due to a fault at the metering location or - the replacement takes place due to a short-term calibration law requirement (i.e. deviating from the plannable cycle) or in the context of failed random sampling. ## Process flow from the perspective of the MSB (GMSB) \nSystem diagram: Ersteinbau einer mME in eine bestehende Messlokation — view of MSB\n\n\nCustomer backend system\n\nMACO APP · MSB (entsprich…\n\nMarket partner\n\n\n\n1. Vorabinformation zum\nGerätewechsel\n\nLF\n\nAS4\n21029\n\nUpdate transaction\n\n\nUpdate process data\n\nAPI\n"} gesamt={"\nSequence diagram: Ersteinbau einer mME in eine bestehende Messlokation — view of MSB\n\n\nBackend (customer)\n\n\nMACO APP · MSB (entsprich…\n\n\nLF\n\n\n1. Vorabinformation zum Gerätewechsel\nAS4 · PI 21029\n\nUpdate transaction\nUpdate process data\n"} titel="GMSB" /> ## Process steps ### Advance information on the device replacement
**Check identifiers** - [21029](/en/schnittstellen/202604/pruefi/IFTSTA/PI_21029) — Advance information · AS4
**Flow**
  1. Message to **LF** · AS4
  2. **Write endpoint** - Transaction updated — [Update process data](/en/api/202604/backend-schreiben-msb/updateprocessdata#prozessdaten-aktualiseren) `POST /updateProcessData` Try it out Updates the existing transaction in the backend once the message has been created.
## Process information Wording of the consolidated version, profile ch. 3.4.1, pp. 57–58.
  1. ### Error case #### Result in the error case If the initial installation of the mME could not take place within the installation time window and is still intended, this information is to be started again for a further initial installation. #### Error cases z.B.: - Access to the metering location not possible within the time period
  2. ### Further requirements The information obligations under § 37 (2) MsbG remain unaffected.
  3. ### First message The party involved on this page is itself the sender of: „Advance information on the device replacement“ to **LF** (step 1).
  4. ### Objective All LF are informed in advance about the intended initial installation of a mME in an existing metering location.
## Other views of the process The same process through the eyes of the other parties involved: the same steps, each read from their point of view. - [View LF](/en/prozessdoku/202604/LF/WiM-Teil1-ersteinbau-einer-mme-in-eine-bestehende-messlokation) — LF *The steps are the **possible** messages of this process, not a sequence — the source lists neither conditions nor alternatives. The small box on the step names the own view on the left: with **←** it receives, with **→** it sends. Collapsed steps run between other market partners.* The source does not yet name the event that triggers these steps. Applies to: [1](#schritt-1)