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Comment: Updated description to match current membership and process.

The DM Technical Control Team has responsibility for issues similar to those of the LSST Configuration Control Board, but restricted to those contained within the DM subsystem. The TCT reviews and approves recommends approval of changes to all baselines in the LSST Data Management System, including proposed changes to the DM System Requirements' (DMSR), reference design, sizing model, i.e. any LDM-xxx baselined document.  The TCT makes sure these changes don't get into the baseline without proper change control.  Note that the TCT does not author the Technical Baseline and has no specific technical deliverable charter and that final approval of all changes is by the DM Subsystem Lead, but it does validate that the form and content of the Technical Baseline is consistent with LSST project standards such as the System Engineering Management Plan (SEMP).  Specific responsibilities for development of the Technical Baseline and evaluation of the content versus LSST and DM requirements are defined in the LSST Organization and Charter (LDM-294).

The TCT also serves to resolve Requests For Comments (RFCs) which have been appealed to it after failure to reach consensus or that it deems important.

  • Charter/purpose
    • Ensure that the DM Technical Baseline (LDM-xxx) documents are baselined and once baselined only changed when necessary, according to LSST and DM configuration control processes

  • Membership
    • Co-Chaired by the DM Project Manager and DM Project ScientistSystem Engineer.
    • Members include the DM System ArchitectProject Scientist, DM System Interfaces Scientist, DM SQuaRE Technical ManagerFor on-line virtual meetings, if a quorum is not reached within one week, the DM Project Manager and the DM Project Scientist will make a unilateral decision
  • Responsibilities
    • Determines when specification and deliverables are of sufficient maturity and quality to be baselined (placed under configuration controlled status) or released. The TCT reviews and approves proposed changes to baselined items.
    • Reviews and approves/rejects proposed changes to baselined items
Meetings and Notices  

The TCT meets whenever a request is made for approval to change baseline

    • Architect, DM Data Processing Lead, and DM Pipeline Scientist.
    • Members may designate a proxy if they are unable to attend a meeting or give an item sufficient consideration.

  • Responsibilities
    • Recommend approval, recommend disapproval, or delegate decision for baseline items (LDM controlled documents).
    • Adopt, reject, or delegate decision for RFCs that fail to reach consensus or are explicitly appealed.
Meetings and Notices

Changes to or additions to the set of LDM controlled documents are submitted via RFCs with component "TCT".  Appealed RFCs are placed in "Flagged" status by the RFC owner.  Questions or comments by TCT members are usually made directly on the RFCs, and votes by TCT members are made by commenting on the RFCs.

The TCT recommends approval/disapproval or adoption/rejection or delegates the decision; the DM Subsystem Lead makes the final decision.

From time to time the TCT may meet to have in-depth discussions of issues before it and to come to decisions.

  See the TCT Meetings and Notices for the record of decisions taken by prior versions of the TCT.  Note that in R&D, the TCT was responsible for the baselining of software libraries and standards and many decisions are noted about this, but this has since then been delegated to the DM System Architect.


To start the chain of events, the interested party creates an RFC describing the proposed change , with component "TCT"; refer to:

Discussion and Decision Making Process