LIGO Document M1200274-v4

Engineering Change Request (ECR) Process

Document #:
LIGO-M1200274-v4
Document type:
M - Management or Policy
Other Versions:
Abstract:
Memo defining and imposing the Engineering Change Request (ECR) Process.

The Engineering Change Request (ECR) process defined in this memorandum is imposed for all changes to the detector (interferometer) system, as well as the vacuum system and the facilities that directly support the detector. In all cases an approved ECR will result in changes in design/build documentation. The record of review and approval of these changes is handled by the DCN process which is defined in E030350.

Authors:
Notes and Changes:
v4: Abstract updated. CIT.

4/19/2016 D. Coyne: Pending change to be incorporated:
If funds are required to execute an ECR (other than staff labor time), the account number(s) (for materials, supplies, equipment, services, etc.) shall be defined at the time of ECR approval by Systems Engineering. The account number shall be included in the "Abstract" field of the DCC entry for the ECR for ready reference.

1) Development costs are typically borne by either:
a) the developing group's operations account(s), and/or
b) an R&D account, and/or
c) a Fabricated Equipment account (drawn from Ops or R&D funds) if warranted

2) Production & installation costs are typically borne by the "upgrade/enhancement" funds for each observatory, and are allocated into sub-accounts by the systems and the business group, as defined in M1500001

5/11/2016 D. Coyne: Pending clarification to be incorporated:
ECRs should, in general, be written & approved before one spends significant time and effort on designing or prototyping (not just before asking for production funds); The intent is to not waste labor time if the proposed change will not be approved.
e.g. see Figure 9, "Process Diagram: ECR", in M1500313-v2, "Process Flow for Engineering Operations of the LIGO Detector Systems"

9/30/2021 D. Coyne: Pending clarification to be incorporated:
One caveat or use-case (which is apparently not covered in the above referenced documentation) is an R&D project. If some research is required to determine how to solve a problem, or implement a concept, then this should be covered by the R&D proposal review process. The R&D proposal process, including the criteria for requiring an R&D proposal review, is defined in LIGO-L1200202. In other words, if we're unsure if a proposed change or approach will work and some research is required to first establish the efficacy or validity of the approach this is covered in the R&D review process, not the ECR process. If the R&D is successful a subsequent change request to implement is then covered by an ECR.


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