The form is signed. The machine is not checked.

Walk into most VMC shops in Ludhiana or Coimbatore and ask for the daily maintenance record. You will get a file. Inside it, a bi-monthly preventive maintenance sheet with 40-odd lines, printed from a machine supplier’s PDF, signed in the same blue pen every day. The coolant is low. The way-lube reservoir is at the bottom mark. There is a film of oil under the X-axis cover. The form says all clear. Nobody is lying, exactly. The operator has been handed a document written for a maintenance technician, given two minutes to fill it, and told to tick. So he ticks.

The problem is not the operator. It is that the daily checklist and the preventive maintenance schedule have been merged into one document, and the operator has been made responsible for both. They are different jobs, done by different people, at different intervals. Separate them and the daily sheet becomes something an operator can finish before the first part and a supervisor can verify without an argument.

Step 1: Split the daily check from the PM schedule

A daily operator check covers what the operator can see, hear, feel or top up at the start of his shift. A preventive maintenance schedule covers what a maintenance technician does with tools, gauges and lock-out procedures. The two should not share a page.

Machine manufacturers already make this distinction. The Hurco VM Series maintenance manual, for example, separates daily checks (every 8–10 hours) from weekly, monthly, quarterly, six-monthly and annual tasks. The daily list includes checking and maintaining lubricant levels, cleaning the tool changer arm tool lock pins and gripper fingers, checking tool condition, lubricating the non-motorised spindle taper, checking FRL air pressure, checking coolant level, and warming up the machine. The monthly list includes inspecting conduit, connectors and external wiring; the quarterly list includes measuring ground impedance. Those are not operator tasks.

Published daily machine tool checklists follow the same logic. A sample daily checklist from a machine tool supplier is designed to be completed at the beginning and end of each shift and records operator name, date, machine ID, location and service due date. It does not ask the operator to measure backlash or inspect the electrical cabinet.

Your daily sheet should have one owner: the operator. Your PM schedule should have another: the maintenance incharge. If the operator’s name is on a line about ground impedance, the form is wrong.

Step 2: Pick six to eight lines, not forty

The single biggest reason daily checklists fail is line count. A 40-line form is a monthly or quarterly document. An operator starting a shift has time for six to eight checks, done properly, before the first component goes on the table. More than that and he will tick without looking.

Go to your own machine manual’s daily section. Not the monthly, not the quarterly. The daily section. For most VMCs, the daily items fall into a small number of categories:

• Cleanliness: swarf removed from the work table and front shutter, dust cleared between the slide and work table. A sample VMC preventive maintenance form in circulation lists exactly this as its first daily item.
• Lubrication: way-lube reservoir at the mark, no alarm on the control, oil visible at the flow indicators.
• Coolant: level at the mark, condition acceptable, nozzles clear.
• Pneumatics: air pressure at the set point on the gauge, FRL bowl drained, no water in the line.
• Spindle and taper: taper wiped clean, no scoring or coolant residue, tool seated correctly.
• Tooling and workholding: cutting tools inspected for wear or damage, vice or chuck secure.
• Guards and safety: guards fitted, emergency stop tested where appropriate.
• Warm-up: spindle warm-up cycle run before the first cut.

That is eight categories. Pick the ones that matter for your machine and your work. If you run aluminium with through-spindle coolant, coolant flow is a daily line. If you run castings with heavy swarf, chip clearance is a daily line. If your machine sits idle overnight in a dusty shed, the way-cover wipe-down is a daily line. Do not copy another shop’s list. Copy your manual’s daily section and cut it to what the operator can actually judge.

Step 3: Write each line as a condition, not an instruction

This is where most checklists lose the operator. A line that says “inspect coolant condition” gives him nothing to decide. A line that says “coolant level at the mark on the tank” gives him a yes or no. A line that says “check lubrication system” is a maintenance instruction. A line that says “way-lube reservoir above the MIN line” is a shift check.

Rewrite every line as a condition with a visible answer:

• Instead of “check air pressure”: “Air pressure gauge reads at the set point marked on the FRL.”
• Instead of “inspect coolant”: “Coolant level at or above the tank mark; no oil film on the surface.”
• Instead of “check way lubrication”: “Oil visible in the flow indicator on X, Y and Z; reservoir above MIN.”
• Instead of “check spindle taper”: “Taper wiped clean with lint-free cloth; no scoring, no coolant residue.”
• Instead of “check tooling”: “All tools in the magazine undamaged; no chipped edges on the active tool.”
• Instead of “check guards”: “Enclosure door interlock closes and holds; no guard panel missing.”
• Instead of “listen for unusual noise”: “During warm-up cycle, no grinding, knocking or squealing from spindle or axes.”
• Instead of “check for leaks”: “No oil or coolant pooling under the machine or on the way covers.”

If a line cannot be answered pass or fail by looking, listening or reading a gauge, it does not belong on the daily sheet. Move it to the PM schedule.

Step 4: Give every line a pass/fail box and a named escalation

A tick box is not a decision. A pass/fail box is. The 40-check CNC maintenance template published by MapTrack uses Pass / Fail / N/A responses for each item rather than free-text remarks, and that is the right model for a daily sheet too. The operator marks P or F. If F, he does something specific.

That something must be named on the form. A fail box with no escalation is a comment box. The operator writes “coolant low” and nothing happens until the pump cavitates three days later. Instead, each fail line should carry a short instruction:

• Coolant level fail: Top up before starting. If level drops again within the shift, stop and call the shift supervisor.
• Air pressure fail: Do not start the cycle. Call the maintenance incharge. Record the gauge reading.
• Oil leak fail: Do not run the machine. Tag it and call the maintenance incharge.
• Spindle noise fail: Stop the warm-up. Call the maintenance incharge before any cutting.
• Taper scoring fail: Do not load a tool holder. Call the maintenance incharge.

The escalation should name a person and a time, not a department. “Call the shift supervisor before the next cycle” is an instruction. “Report to maintenance” is a hope.

One safety point that belongs on the form itself: the Hurco manual states that the machine enclosure must not be accessed while machine power is on, and that lock-out/tag-out procedures must be observed before performing any maintenance inside the enclosure. If a daily line requires reaching inside the enclosure, it is not an operator line. Move it to the PM schedule and put it under lock-out.

Step 5: Design the form for the shift, not for the file

The form should fit on one page and be usable at the machine. That means:

• Machine ID and hour meter reading at the top. The hour meter is the single most useful field on the sheet. It lets the supervisor reconcile the form against the production log and makes back-filling visible. If the hour meter reads 14,320 on Monday and 14,320 on Tuesday, the form was filled at the desk.
• Date and shift at the top. A daily sheet that does not record which shift it covers cannot be verified.
• Operator name and signature at the bottom. Not initials in a corner. A signature is a claim that the checks were done.
• No separate logbook. The form is the log. If the operator has to copy faults into a second register, the second register will be empty.
• A remarks line for each fail, not for each pass. Pass lines need no comment. Fail lines need the gauge reading, the leak location, the noise description.

The sample daily checklist from Kenequip records operator name, date, machine ID, machine location and service due date at the top, and includes a faults log line at the bottom. That is the right shape. Adapt it to your machine and your shift pattern.

Step 6: Set the review rhythm before you print the first sheet

A checklist with no review is a ritual. Before the first sheet goes on the machine, decide who reads it and when:

• Daily: The operator completes the sheet before the first part. The shift supervisor glances at it at the start of the shift, not at the end of the week.
• Weekly: The supervisor verifies the forms against the production log and the hour meter. Any form with all passes and a maintenance log showing a coolant top-up on the same day is a form to question.
• Monthly: The maintenance incharge reviews all fails. A fail that repeats three weeks running is either a machine problem the PM schedule is not addressing or a line written at the wrong interval. Either way, the daily sheet is the wrong place to keep recording it. Fix the machine or move the line.
• Quarterly: Revise the sheet. Cut any line that is consistently skipped or marked pass without inspection. Add any line that the maintenance log shows was needed but not caught.

The review rhythm is what separates a checklist from a decoration. If nobody reads the form, nobody will fill it honestly.

Step 7: Pilot on one machine for two weeks

Do not roll out to all four VMCs on Monday. Pick one machine, one operator, one shift. Print eight lines. Run it for ten working days. Then count:

• How many shifts produced a completed form? If the answer is fewer than eight out of ten, the form is too long or the timing is wrong.
• How many fails were recorded? If the answer is zero across ten days, the operator is ticking, not checking. Rewrite the lines as gauge readings or visible conditions and run again.
• How many fails were escalated? If fails were recorded but no one was called, the escalation path is not real. Name a person and a phone number on the form.
• Which lines were consistently skipped? Cut them or move them to the PM schedule.

A hypothetical example from a 60-person auto-component shop running four VMCs: the first version of the sheet had fourteen lines. Over two weeks, the coolant and air-pressure lines were ticked pass every day, but the maintenance log showed a coolant top-up on six of those days. The lines were being signed, not checked. The fix was to rewrite them as gauge readings — “coolant level at the mark” and “air pressure at 0.6 MPa on the gauge” — and to require the operator to write the gauge reading, not tick a box. Completion dropped for three days, then stabilised, and the coolant top-ups became visible before the pump ran dry. That is the point of the form: not to prove the operator did his job, but to make the machine’s condition visible before it becomes a breakdown.

What not to put on the daily sheet

Some items appear on every borrowed checklist and belong nowhere near an operator’s daily form:

• Backlash measurement. Requires a dial indicator, a lock-out and a cool machine. The MapTrack template advises locking out the machine and letting the spindle, drives and coolant cool to ambient before measuring, so thermal expansion does not distort bearing or alignment readings. That is a PM task.
• Electrical cabinet inspection. Requires a qualified person and lock-out. Not an operator line.
• Ground impedance measurement. A quarterly or annual task, not a shift task.
• Coolant concentration and pH testing. Useful, but requires a refractometer and a baseline. Put it on the weekly PM schedule, not the daily sheet.
• Spindle run-in. A monthly procedure, not a daily one.

The daily sheet is for what the operator can see, hear, feel or top up. Everything else goes on the PM schedule, with the maintenance incharge’s name on it.

Frequently asked questions

How many lines should a daily VMC checklist have?

Six to eight. Enough to cover cleanliness, lubrication, coolant, pneumatics, spindle taper, tooling, guards and warm-up. More than that and the operator will tick without looking. If your manual’s daily section has more items, decide which ones matter for your machine and your work, and move the rest to the weekly schedule.

Should the operator check coolant concentration every day?

No. Concentration testing needs a refractometer and a clean sample. Put it on the weekly PM schedule. The daily check is level and visible condition — no oil film, no sludge, nozzles clear.

What if the operator marks a fail but the maintenance incharge does not respond?

Then the form is dead. The escalation path must name a person and a time, and that person must respond. If the maintenance incharge cannot respond within the shift, the machine should be tagged out until he does. A fail that produces no action teaches the operator that fails are not worth recording.

Can we use a digital checklist on a tablet?

Yes, if the tablet is at the machine and the form takes the same time as paper. A digital form that requires logging in, navigating three screens and typing a comment for every pass will be completed less often than a paper sheet. Start with paper, get the lines right, then digitise the same eight lines.

Does the daily checklist replace the preventive maintenance schedule?

No. The daily checklist catches what changes between shifts — low coolant, a leak, a noisy spindle, a chipped tool. The PM schedule catches what changes over weeks and months — filter condition, backlash, oil condition, electrical connections. Both are needed. The mistake is putting the PM schedule on the operator’s daily form.

What records should we keep for audit or customer requirements?

Keep the completed daily sheets and the PM schedule records for the period your customer or quality system requires. The daily sheet with machine ID, hour meter, date, shift, operator signature and fail remarks is the evidence that the machine was checked. The PM schedule with the maintenance incharge’s sign-off is the evidence that periodic maintenance was done. Do not rely on a single combined form for both.