Autumn-Winter Off-Peak Production in Glass: Adjusting Electrode Inventory Management

The off-peak production schedule in autumn and winter affects the operating rhythm of glass furnaces. Some plants use the period to carry out maintenance, while others continue running at reduced load. Once the operating mode changes, electrode consumption rates and spare-part demand change with it, and inventory management must be adjusted accordingly.

Two arrangements created by off-peak production

One is shutting down the furnace for maintenance, replacing refractories and electrodes in a concentrated campaign, which pushes spare-part demand up in the short term. The other is reducing pull rate and continuing operation, which lowers electrode load and slows consumption but increases process fluctuations. The two arrangements place different demands on spares and cannot be executed under a single plan.

Stocking for maintenance-driven demand

Maintenance projects should be scheduled backward from the construction milestones: lock the primary specification first, then configure spare units by hole position. Deliveries should arrive slightly before bricklaying begins to avoid long-term storage on site. For non-standard sizes, release billet material immediately after the drawing is confirmed to cut waiting time.

Observing low-load operation

At reduced load, glass melt temperature and convection weaken, and electrode current distribution may become more uneven. Watch the current variation and end condition of individual electrodes to avoid local overcooling that causes glass quality fluctuation. At this stage, electrode position should not be adjusted aggressively, to avoid introducing new disturbances.

Inventory control approach

Keep a small safety stock of standard sizes and lock special sizes to specific projects. Split inventory into "ready to use" and "project-dedicated" categories so that cancelled projects do not tie up stock long term. Review consumption records once a quarter and correct safety stock according to actual replacement volumes rather than carrying forward the plan set at the start of the year.

Safety management during the off-peak period

At low load, furnace temperature and glass flow deviate from design conditions, and the thermal stress distribution in electrodes and blocks changes accordingly. Increase the inspection frequency of glass level, temperature and current on site, and record any abnormality promptly. For shutdown maintenance, control the cooling curve to prevent rapid cooling from cracking the blocks.

Keeping suppliers informed

Once the off-peak schedule is fixed, tell the supplier in advance about possible demand changes so they can adjust production scheduling. If maintenance is postponed, cancel or defer orders promptly to reduce inventory pressure on both sides. The earlier the information is shared, the fewer rush orders are needed.

How to conduct the annual review

After the off-peak period, summarize actual operating days, electrode replacement volumes and inventory changes, and compare them with the plan made at the start of the year. Where the gap is large, analyze the cause: maintenance delay, load change or a difference in reporting basis. Use the review to correct next year's spare-part budget. For companies operating multiple sites, surplus spares can be transferred between sites to avoid duplicate purchasing; confirm specification and lot status before transfer.

Inventory records should be counted every six months, and any mismatch between physical stock and book stock investigated promptly. Off-peak production is a phased arrangement, so the inventory strategy should change with it rather than follow the same standard all year.

Putting the off-peak schedule, maintenance records and inventory changes into a single table makes demand patterns easier to see and lets the next planning cycle reference them directly.

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