A cleaning task with no time estimate rarely survives a maintenance review. It gets pushed to Friday, then skipped. The fix is not a better spreadsheet. It is treating the clean like any other planned job: write down the scope, break it into blocks, time those blocks once, and keep the numbers.
The approach below works for machine shops, assembly halls, packing areas and utility corners. It deliberately says nothing about equipment at the start, because the machine only enters the estimate once the scope is on paper.
Describe the zone before you count hours
Walk the area with the person who works in it, and record four facts for every zone:
- Soil type. Cutting fluid with chip fines, hydraulic oil, grinding dust, food residue, or a mixture of them. Mixed soil takes longer than a single soil, because the order of operations changes.
- Surface. Painted frames, stainless guarding, powder-coated panels, concrete with cracks and expansion joints. Porous and damaged surfaces hold soil and usually need a second pass.
- Access. Fixed guarding, clearances under a machine base, cable trays, sensors that must be covered, carts and pallets that must be moved first.
- Working window. A planned shutdown, a shift change, or a clean performed while the next line keeps running. The window sets how many people you can put on the job and how much water you are allowed to use.
Group zones by how they behave, not by department name. A compressor corner and a gearbox stand usually need the same method, while two machines in the same shop may need different ones. A list of six behaviour groups is far easier to schedule than a list of thirty room names.
Plan in two units, not one
Discrete equipment and open floor are different jobs, so they need different planning units. Mixing them is the most common reason a cleaning estimate collapses.
| Zone type | Unit to plan in | What actually drives the time |
|---|---|---|
| Machine shop, CNC area | Per machine | Enclosures that must be opened, chip conveyors, thickness of the oil film, clearance around the base |
| Assembly hall | Per running metre of line | Access under frames, floor between pedestals, whether neighbouring stations stay in service |
| Packing and dispatch | Per square metre of floor | Residue type, forklift traffic, drainage falls, open expansion joints |
| Utility corners: pumps, compressors, gearboxes | Per unit | Leakage history, distance to the nearest power and water point, electrical cabinets nearby |
| Canteen or kitchen area | Per appliance | Age of the grease build-up, and whether the area must stay open during the job |
If a zone cannot be described in one of these units, the scope is not finished yet. Go back and look at it again rather than guessing an hour figure.
Split the job into five time blocks
- Preparation and access. Lock-out, removing guarding, covering cabinets and sensors, moving carts out of the way. This is the least predictable block, so time it honestly instead of assuming it away.
- Dry removal. Sweeping or vacuuming loose chips, dust and standing liquid before anything wet touches the surface. Teams that skip this almost always overrun, because loose debris turns wash water into sludge that someone has to clear by hand.
- Surface work. The degreasing and washing pass itself, counted per machine or per square metre.
- Rinse and dry. Frequently the longest block when the method produces a lot of water. This is where the choice of equipment changes the total more than anywhere else.
- Restart and sign-off. Refitting guards, wiping contact surfaces, and the inspection that lets production take the area back.
Estimate each block on its own, add a contingency for the first cycle only, then re-time the job after the second and third cleans. From that point the measured figures become your standard, and the estimate stops being an argument.
The cleaning method is where the estimate moves most
Two buyers can clean the same zone with the same crew and get very different durations, because the method sets the size of blocks three, four and five:
- Cold water and detergent. Needs dwell time, mechanical scrubbing, and one or more rinse passes. Floors stay wet, so the restart block grows, and someone has to handle and dispose of the chemical.
- High-pressure hot water. Removes soil faster, but throws a lot of water around. Budget time for mist containment, drainage and clearing the runoff.
- Steam. Heat does most of the work, so scrubbing and rinsing shrink. Industrial steam cleaning equipment uses little water and little or no detergent, which is why the rinse-and-dry block is shorter and the area can be handed back sooner. Where a factory machinery degreasing job involves thick, aged oil, the wet-steam pass lifts the bulk of it and the dry-steam pass finishes the surface.
Two features matter more to your schedule than raw power. The first is a unit that switches between dry and wet steam, so the operator does not stop one job to set up another. The second is tank capacity and water supply against the length of a continuous job; a machine that has to stop for a refill every twenty minutes adds more time than the specification sheet ever suggests.
Ask every supplier for a real specification sheet
A usable sheet tells you, in plain figures:
- Working voltage and heating power, so you can check the supply at the point of use. A fixed unit such as the PowerDe HW02 is listed at 220 V and 6 kW heating power.
- Steam temperature and vapour pressure, which decide how fast hardened soil releases. The same page lists 160 °C and 0.8 MPa.
- Tank volume and water inlet, which decide how long one run lasts. The HW02 is listed with an 80 L stainless tank and a tap-water inlet.
- Available modes, footprint, and the protections fitted, such as leakage, short-circuit, over-temperature, over-voltage and low-water cut-offs.
Treat those figures as a reference for what to ask any supplier, not as a claim that one model suits every bay. Match the numbers to your own supply, floor space and soil.
Time it once, on purpose
Before you commit to a programme or a machine, run one controlled pilot:
- Pick one representative machine and one small floor section with the worst realistic soil, not the easiest one.
- Assign two people and record the five blocks separately, in minutes, including the walk to fetch equipment.
- Note every stop caused by access, refilling, or waiting for a surface to dry.
- Repeat once with the method adjusted, and compare the two records.
The pilot gives you a defensible standard and shows you which of the five blocks is worth attacking first. In most plants it is preparation or drying, not the washing itself.
Before the order goes through
- Confirm the power available where the work happens, and how far the hoses can reach from it.
- Decide between a fixed unit at a wash point, a hand-pushed unit for moving between areas, or a driving-style unit for large floors and long distances.
- Check that the supplier can build to your window and soil conditions; customized steam cleaning equipment is usually the right route when standard configurations do not fit the space or the shift pattern.
- Ask what happens after delivery: spare parts, documentation, and who supports the machine when it stops in the middle of a shutdown.
Cleaning time is estimable once you describe the zone honestly, plan in the right units, and split the job into blocks you can measure. Do that, and the equipment question answers itself: you are no longer buying a machine, you are buying back the hours that your pilot showed you where they were lost.
