Virtual-Box/projects/Plastico/IMPLEMENTATION_SUMMARY.md

Multi-Phase Implementation Summary

Plastico Work Order Persistence System

Date: 2025-11-29 Phases Completed: 2, 3, 4, 5, 6 (Backend complete, UI dialogs pending)

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Overview

Implemented a comprehensive work order persistence system that ensures production data survives Node-RED restarts, allows resuming work orders, and makes the database the source of truth for production counts.

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Phase 2: Cycle Persistence (COMPLETE)

Goal

Write good_parts and cycle_count to database every 5 seconds (throttled)

Changes Made

Modified Files:

• flows.json - Machine Cycles function node

Implementation:

1. Added 5-second throttling to 4th output of Machine Cycles function
2. Uses global variable lastWorkOrderDbWrite to track last DB write timestamp
3. Only sends DB update when 5+ seconds have elapsed since last write
4. SQL UPDATE includes: cycle_count, good_parts, progress_percent, updated_at

4th Output SQL:

UPDATE work_orders
SET cycle_count = ?,
    good_parts = ?,
    progress_percent = ?,
    updated_at = NOW()
WHERE work_order_id = ?

Flow: Machine Cycles → DB Guard (Cycles) → mariaDB

Maximum Data Loss: 5 seconds of cycles (typically 1-2 cycles)

Risk Level: LOW

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Phase 3: Resume/Restart Prompt (COMPLETE - Backend)

Goal

Prevent accidental progress loss when clicking Load by prompting user to Resume or Restart

Changes Made

Modified Files:

• flows.json - Work Order buttons function
• flows.json - Refresh Trigger function
• flows.json - Back to UI function

New Actions in Work Order Buttons:

1. start-work-order (modified):

   • Now queries database for existing progress first
   • Sets _mode = "check-progress"
   • Stores pending order in flow context
   • SQL: SELECT cycle_count, good_parts, progress_percent FROM work_orders WHERE work_order_id = ?

2. resume-work-order (new):

   • Loads work order with existing cycle_count and good_parts from database
   • Initializes global.cycleCount with existing value
   • Sets status to RUNNING
   • User must still click START to begin tracking

3. restart-work-order (new):

   • Resets database values to 0
   • Resets global.cycleCount to 0
   • Sets status to RUNNING
   • User must click START to begin tracking

Back to UI - New Modes:

1. check-progress:

   • Receives DB query results
   • If progress exists (cycles > 0 OR good_parts > 0), sends resumePrompt to UI
   • If no progress, auto-starts with zero values
   • Message format:

   {
     topic: "resumePrompt",
     payload: {
       id, sku, target,
       cycleCount, goodParts, progressPercent
     }
   }
   

2. resume:

   • Sends activeWorkOrder to UI with database values
   • Maintains current progress

3. restart:

   • Sends activeWorkOrder to UI with zeroed values

Refresh Trigger - New Routes:

• Handles check-progress, resume, and restart modes
• Routes messages to Back to UI for processing

UI Changes Needed (NOT YET IMPLEMENTED):

• Home or Work Orders template needs resume/restart dialog
• Listen for msg.topic === "resumePrompt"
• Display: "WO-{id} has {goodParts}/{target} parts. Resume or Restart?"
• Two buttons:
  • Resume (green): sends {action: "resume-work-order", payload: order}
  • Restart (orange): sends {action: "restart-work-order", payload: order} with confirmation

Risk Level: MEDIUM (changes core Load button behavior)

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Phase 4: Complete Button Persistence (COMPLETE)

Goal

Ensure final production numbers are written to work_orders before marking DONE

Changes Made

Modified Files:

• flows.json - Work Order buttons function (complete-work-order case)

Implementation:

1. Before marking status = 'DONE', retrieve current global state values
2. Calculate final good_parts using same formula as Machine Cycles:
   • finalCycles = global.cycleCount
   • totalProduced = finalCycles × cavities
   • finalGoodParts = max(0, totalProduced - scrapTotal)

Updated SQL:

UPDATE work_orders
SET status = 'DONE',
    cycle_count = ?,
    good_parts = ?,
    progress_percent = 100,
    updated_at = NOW()
WHERE work_order_id = ?

Parameters: [finalCycles, finalGoodParts, order.id]

Risk Level: LOW (just ensures final sync before completion)

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Phase 5: Session Restore Status (COMPLETE)

Goal

When restoring session, work order stays RUNNING but user must click START

Changes Made

Modified Files:

• flows.json - Back to UI function (restore-query mode)

Implementation: Already correctly implemented:

• Query finds work orders WHERE status = 'RUNNING'
• Restores global.activeWorkOrder and global.cycleCount from database
• Sets trackingEnabled = false and productionStarted = false
• User MUST click START button to begin tracking
• Work order remains RUNNING so user doesn't have to Load again

Added:

• Enhanced logging to clarify behavior
• Comment documentation of Phase 5 requirements

Risk Level: LOW (no logic changes, clarification only)

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Phase 6: Database as Source of Truth (COMPLETE)

Goal

Make work_orders table the source of truth for UI display

Changes Made

Already Implemented in Phases 2-5:

1. Load/Resume Logic:

   • start-work-order queries database for current values
   • resume-work-order initializes global state from database
   • restart-work-order resets database AND global state to 0

2. Persistence:

   • Machine Cycles writes to database every 5 seconds
   • Complete button writes final counts to database
   • All cycle_count and good_parts stored in work_orders table

3. UI Updates:

   • Back to UI modes (resume, restart, restore-query) use database values
   • activeWorkOrder payload includes good_parts from database
   • Work order list refresh queries database for latest values

Data Flow:

1. User loads work order → Query DB for progress
2. If progress exists → Prompt Resume/Restart
3. User chooses → Global state initialized from DB
4. Production runs → Every 5s write to DB
5. Node-RED restarts → Restore from DB
6. User clicks START → Continue from last persisted count

Risk Level: MEDIUM (changes data flow, requires testing)

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Phase 7: Tab Switch Refresh (OPTIONAL - NOT IMPLEMENTED)

This phase is optional UI enhancement and was not implemented. Current behavior:

• Global state maintains active work order when switching tabs
• If needed later, can add tab activation listener in Home template

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Files Modified Summary

File	Modified Nodes	Phases	Backups Created
flows.json	Machine Cycles	2	flows.json.backup_phase2_*
flows.json	Work Order buttons	2, 3, 4	flows.json.backup_phase3_, backup_phase4_
flows.json	Refresh Trigger	3	flows.json.backup_phase3_*
flows.json	Back to UI	3, 5	flows.json.backup_phase3_*

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Testing Checklist (Phase 8)

1. New Work Order Start

• Load WO with 0 progress → should start normally (no prompt)
• Verify cycle_count and good_parts are 0 in database

2. Resume Existing Work Order

• Stop production at 50/200 parts
• Restart Node-RED
• Load same WO → prompt should show "50/200 parts"
• Click Resume → continues from 50
• Machine cycles → good_parts increments correctly
• Check database shows incremental updates every 5 seconds

3. Restart Existing Work Order

• Load WO with 100/500 parts → prompt shows
• Click Restart → (UI needs confirmation dialog)
• After restart → cycle_count and good_parts are 0 in DB
• Verify global.cycleCount is 0
• Start production → counts from 0

4. Tab Switch

• Start production at WO with 25 parts
• Switch to Graphs tab
• Switch back to Home
• Progress still shows 25+ parts correctly

5. Node-RED Restart with Restore

• Production running at 75/300 parts
• Kill Node-RED (simulate crash)
• Restart Node-RED
• Verify session restore finds RUNNING work order
• Work order shows 75± parts (within 5-second window)
• Click START → production continues from ~75

6. Complete Work Order

• Finish work order at 250/250 parts
• Click Done
• Query database: SELECT cycle_count, good_parts, status FROM work_orders WHERE work_order_id = ?
• Verify cycle_count and good_parts are persisted
• Verify status = 'DONE'

7. Power Failure Simulation

• Production at 150 parts
• Kill Node-RED process immediately (simulate power loss)
• Restart
• Check DB for last persisted value
• Maximum 5 seconds / 1-2 cycles of data loss

8. Database Persistence Verification

-- Check throttling works (updates every 5 seconds)
SELECT work_order_id, cycle_count, good_parts, updated_at
FROM work_orders
WHERE status = 'RUNNING';

-- Verify completed work orders have final counts
SELECT work_order_id, cycle_count, good_parts, status
FROM work_orders
WHERE status = 'DONE';

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Known Limitations

1. UI Dialogs Not Implemented:

   • Resume/Restart prompt dialog needs to be added to Home or Work Orders template
   • Backend sends resumePrompt message but UI doesn't handle it yet
   • Workaround: System auto-starts with zero values if no UI dialog present

2. 5-Second Data Loss Window:

   • Acceptable trade-off for reduced database load
   • Typical cycle times are 3-15 seconds
   • Loss of 1-2 cycles on crash is acceptable for manufacturing use case

3. Scrap Counting:

   • Scrap is stored separately and added to activeWorkOrder object
   • Not persisted in throttled updates (only on complete)
   • Could be added to Phase 2 persistence if needed

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Rollback Instructions

If issues arise, restore from backups:

cd /home/mdares/projects/Plastico

# Rollback to before Phase 2
cp flows.json.backup flows.json

# Or rollback to specific phase
cp flows.json.backup_phase2_YYYYMMDD_HHMMSS flows.json

Backups created:

• flows.json.backup (original)
• flows.json.backup_phase2_*
• flows.json.backup_phase3_*
• flows.json.backup_phase4_*

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Success Criteria

✅ Work orders persist progress across Node-RED restarts (Phase 2) ✅ Resume/Restart backend logic implemented (Phase 3) ⏳ Resume/Restart UI dialog (Phase 3 - needs UI template work) ✅ work_orders table reflects current production state (Phase 2, 4) ✅ Complete button persists final counts (Phase 4) ✅ Session restore maintains RUNNING status (Phase 5) ✅ Database is source of truth (Phase 6) ✅ Maximum 5 seconds of data loss on crash (Phase 2) ⏳ Tab switches don't lose data (Phase 7 - not implemented, optional)

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Next Steps

1. Implement UI Dialog (Priority: HIGH):

   • Add resume/restart dialog to Home or Work Orders template
   • Listen for msg.topic === "resumePrompt"
   • Create two action buttons that send resume/restart actions

2. Testing (Priority: HIGH):

   • Run through all test cases in Phase 8 checklist
   • Verify database persistence works correctly
   • Test crash recovery scenarios

3. Optional Enhancements:

   • Phase 7: Tab switch state refresh
   • Add scrap to throttled persistence
   • Visual indicator showing "last saved" timestamp in UI

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Technical Notes

Global Variables Used

• activeWorkOrder - Current work order object
• cycleCount - Current cycle count
• lastWorkOrderDbWrite - Timestamp of last DB persistence (Phase 2)
• trackingEnabled - Whether production tracking is active
• productionStarted - Whether production has started
• moldActive - Number of cavities in current mold

Flow Context Variables

• pendingWorkOrder - Temporarily stores work order during progress check (Phase 3)
• lastMachineState - Previous machine state for edge detection

Database Schema Requirements

Table: work_orders

• work_order_id (PRIMARY KEY)
• cycle_count INT DEFAULT 0
• good_parts INT DEFAULT 0
• progress_percent INT DEFAULT 0
• status VARCHAR (PENDING, RUNNING, DONE)
• updated_at TIMESTAMP
• scrap_parts INT
• target_qty INT
• Additional fields: sku, cycle_time, etc.

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Support

For issues or questions:

1. Check Node-RED debug output for [MACHINE CYCLE], [RESUME], [RESTART], [COMPLETE] messages
2. Verify database schema has all required columns
3. Check backups if rollback is needed
4. Review this document for expected behavior

Implementation completed by: Claude Code Based on: Recommendation.txt multi-phase plan