What Should a Weekly Mold Progress Report Tell You?

Last updated: 2026-09-01 · Reading time: about 4 min

A progress report is not a photo album; it is a status of the critical path in writing. Every weekly report from a mold build should state five things — current stage, dated photos, problems hit, next week’s plan, and any decision needed from you — and a report missing any of the five is a mood update, not a report. This page shows how to read one like an engineer.

Key facts

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  • The five sections are the contract: stage, photos with dates, problems, next-week plan, and decisions requested. Photos without problems and plans are decoration.
  • Problems belong in the report, not in the final week — a shop that reports friction early is managing the schedule; one that reports none for six weeks is managing you.
  • The report is also your early-warning system: cross-check it against the known delay sources and the stalls become visible weeks before they cost a date.

    • Warpage — Part deformation after ejection caused by uneven shrinkage. Amorphous resins warp less (0.4–0.7% shrinkage). Semi-crystalline resins warp more (1.0–2.5% shrinkage). Fix: uniform wall thickness, balanced cooling, optimized gate location, adequate packing pressure. See also related guide.

    Runner system — The channel network that delivers melt from the machine nozzle to each cavity. Cold runner: solidifies between shots, produces runner waste. Hot runner: stays molten, eliminates runner waste but adds $15k–$40k to mold cost. See also related guide.

    What belongs in every weekly report?

    Stage: where the tool is on the five threads — design, procurement, machining, fitting, trials — named precisely enough to verify. Photos: dated, showing the work claimed, from angles that let you see the steel; a photo of a closed mold in a press tells you nothing about the week.
    Problems: what went slower than planned, why, and what it touches on the schedule — silence here is the single most reliable predictor of a bad surprise in month three. Next week’s plan: specific enough that next week’s report can be checked against it, which turns the report from prose into a commitment device. Decisions requested: the questions only you can answer, stated with their deadlines — because answer latency, not machines, is what most builds wait on.
    The lead-time threads make a natural template for all five.

    How do you read the photos like an engineer?

    Photos carry information only when you compare them against the stage claim. A report claiming “core roughing complete” should show a core with visible stock still on the cosmetic faces; one claiming “fitting in progress” should show parting-line spotting blue. Watch for three tells.
    Mismatch: the photo shows an earlier stage than the words claim — ask what the photo is dated and what changed since. Absence: the same angle every week means the interesting work may be happening off-camera; ask for the angle you cannot see. Silence on problems: a build with no reported friction for a month has either a perfect shop or a filtered report, and the base rate favors the filter. None of this is distrust — it is reading.
    The shops that welcome specific questions about their photos are the shops whose reports you can schedule against; the trial records they produce later read the same way — complete, dated, checkable.

    Which questions should you ask back?

  • “What is waiting on us?” — asked every week, it keeps answer latency at zero and surfaces decisions before they stall a thread.
  • “What slipped this week, and what did it move?” — the second half is the important one; a slip that touched nothing on the critical path is information, not alarm.
  • “Show me the steel you bought.” — mill certificates and grade markings for the named grades; the report that can produce them in a day is describing real procurement.
  • “What will the next photo show?” — the commitment question; it converts next week’s plan into a checkable claim.

    • Frequently asked questions

    How often should reports arrive?

    Weekly is the professional default during a build: frequent enough that a stalled week shows immediately, rare enough that the shop writes substance instead of chatter.
    Daily updates are a sign of either a crisis or a micromanager; silence for two weeks is a sign of something worse. Agree the cadence at quotation — it is a one-line contract that pays for itself.

    Should reports come from the project manager or the engineer?

    From whoever owns the schedule, with access to whoever owns the work. A PM-only report reads smoothly and knows little; an engineer-only report knows much and reads roughly. The useful version names both: a PM who consolidates and an engineer whose answers you can request directly when a technical question needs one. Acceptance discussions in particular deserve an engineer on the thread.

    What if the reports are fine but the tool ships late anyway?

    Then the reports were describing intention, not status — the five-section format exists precisely to prevent this. The audit is quick: pick any week, check the photo dates and the promised next-week plan against what actually happened. A pattern of plans never checked becomes a pattern of plans never kept; raise it once, in writing, and watch the next report sharpen.

    Key takeaways

    1. Five sections define a real report: stage, dated photos, problems, next-week plan, decisions requested.
    2. Read photos against the stage claim — mismatch, absence and problem-free weeks are the three tells.
    3. A report you can audit turns into a schedule you can trust.

    If your build reports feel like postcards, send us the last three. You will get the five-section template, the questions that make the next report checkable, and a read on what the silence has been covering — from a named tooling engineer, before any steel is ordered.

    Sources
    LKM — mold base supplier, reference for procurement status in build reporting
    Plastics Industry Association — industry resources on tooling project practice
    ISO 20457:2018 — Plastics moulded parts: Tolerances and acceptance conditions, International Organization for Standardization

    Sources: Plastics Technology · Plastics Technology Online · Society of Plastics Engineers (SPE) · ThomasNet