Warehouse slotting is the job of deciding which product lives in which location, so the lines picked most sit closest to dispatch and at easy heights. This guide is for supervisors and operations managers in Victoria who want pickers walking less and lifting from better positions without rebuilding the warehouse layout.
Why where a line lives decides how long a pick takes
Walking to the location is part of every pick. The pick path, the route a picker takes through the aisles, is set by where the lines sit, so a fast line stored deep in the building drags every picker past a lot of product they do not need.
Layouts drift. New products take the nearest empty gap, a seasonal line stays where the season put it, and a line that was once slow becomes a daily pick. Nobody decides to build a long pick path; it accumulates.
Slotting resets that drift using your own records. A supervisor with a pick list export or a month of pick sheets can do the first pass in an afternoon. A warehouse management system helps, and the post on scanner and WMS skills covers which scanner skills you can train and which you hire for.
Slotting decides where lines live. How orders are released and picked, through batch and wave picking, is covered in a separate guide.
Rank your lines from the last month of picks
The first step is to count pick lines, not units. A pick line is one visit to one location for one product on one order. The walk is the cost you are trying to cut, so a carton of fifty and a single item each count once.
- List. Export or tally the last month of picks by product. A month smooths out a single odd order and still reflects current demand.
- Rank. Sort the list from the most picked to the least picked.
- Split. Draw two lines to create three groups: fast, medium and slow. This is the idea behind ABC analysis in a warehouse, with A for fast, B for medium and C for slow.
Choose where to draw the lines by looking for the points where the picks fall away sharply, not by a fixed percentage. Your own list will show where they are. In this example the drops are modest, so the split is a judgement call.
Example: twelve lines ranked into three groups
Here is an example with hypothetical round numbers. A site picked 3,000 lines last month across twelve products. Ranked from the highest, the picks were 900, 600, 500, 350, 200, 150, 100, 80, 50, 30, 20 and 20.
- Fast group. The three most picked lines, with 900, 600 and 500 picks. Together they account for 2,000 of the 3,000 picks, which is two thirds of the total.
- Medium group. The next four lines, with 350, 200, 150 and 100 picks, for 800 picks in total.
- Slow group. The last five lines, with 80, 50, 30, 20 and 20 picks, for 200 picks in total.
If moving the three fast lines closer to dispatch saves 20 metres a pick, that is 2,000 picks times 20 metres, or 40 kilometres less walking in a month. The figures are illustrative, but you can repeat the arithmetic with your own list.
Match warehouse slotting to frequency and to height
Two questions place every line: how close to dispatch, and how high on the rack.
- Fast lines. Closest to the dispatch end, in the aisles with the shortest route in and out, on the easiest shelves.
- Medium lines. Next along, in the middle of the pick path.
- Slow lines. Furthest from dispatch. Light, easy-to-handle slow lines can take the highest and lowest levels, where a pick takes longer anyway.
For the height rule, WorkSafe Victoria's page on moving or lifting objects says to place frequently moved items, and large, bulky or awkward-to-handle objects, on storage shelves above knee height and below shoulder height. Manual handling is covered in more depth in a separate guide. For slotting, the rule gives you a simple test: the fast group goes in that band first, and so does any line that is large, bulky or awkward to handle, however slowly it moves.
Set putaway rules the whole crew follows
A slotting plan lasts only as long as the putaway locations are respected. A pallet arrives, the assigned location is full, and the putaway operator uses the nearest empty gap. The nearest empty gap is not a rule. It is the habit that created the old layout.
Write a short set of putaway rules and put them where the crew can see them:
- Home location. Every product has one primary pick location, shown on the shelf label and in the system.
- Overflow. When the home location is full, stock goes to a named overflow location for that product, not to the nearest gap.
- Same day record. Any move, new location or overflow is entered in the warehouse management system or the location sheet before the end of the shift.
These rules are practical suggestions for your site, not a standard. What matters is that they are written down and that the next starter hears them in the first week. If you use warehouse labour hire in Victoria, Chandler Personnel runs site inductions on behalf of clients, so you can ask the provider to cover your new location rules in the site induction for the crew it supplies.
Run the re-slot in a quiet week
Moving stock while orders are going out slows both jobs. Choose the quietest week your own records show, and use the post on working out warehouse headcount to compare your busiest and quietest weeks before you commit people.
Move in the order that keeps picking possible: clear the easy shelves nearest dispatch first, bring the fast lines in, then shuffle the medium group, and move the slow group last. Leave every pick face stocked and findable at the end of each day.
Who does the moving and how it is recorded
A re-slot suits a small group working under one leader. The leader holds the plan, tells each person which pallets go where and checks the record at the end of the shift. A few casual or labour hire hands can do the lifting, and experienced pick packers who know your products are useful in the group because they know which lines are awkward.
- Before. Print the plan with old and new locations side by side. Brief the group on the putaway rules and equipment.
- During. Move one line at a time. Relabel the new location, scan or record the move, then clear the old location.
- After. The leader checks a sample of new locations against the record and walks the pick path once to see that it makes sense.
If you need extra hands for the move, the warehousing and logistics staffing page is the place to start with Chandler Personnel.
Related Resources
- Warehouse labour hire in Victoria
- Warehousing and logistics staffing
- Scanner and WMS skills
- Warehouse labour planning
- Pick packer roles
- WorkSafe on moving or lifting
Common Questions About Slotting Your Warehouse for Faster Picks
1. What is warehouse slotting?
Warehouse slotting is the practice of assigning each product to a storage location based on how often it is picked and how it is handled. Fast-moving lines go closest to dispatch and at easy heights, and slow lines go further away, using the racking you already have.
2. How do I decide which products go closest to dispatch?
Count how many times each product was picked last month, rank them from most to least, and split the list into fast, medium and slow groups where the picks fall away. The fast group goes closest to dispatch. Count pick lines, not units, because each visit to a location is a walk.
3. How often should I re-slot a warehouse?
There is no fixed interval. Re-rank your lines whenever the product range or customer mix changes, such as a new contract or a seasonal shift, and check on a regular schedule that suits your site, such as each quarter. A line that was once slow and is now picked daily is the clearest sign that the ranking has drifted.
4. What height should fast-moving lines sit at?
WorkSafe Victoria's page on moving or lifting objects says to place frequently moved items, and large, bulky or awkward-to-handle objects, on storage shelves above knee height and below shoulder height. Treat that band as the first choice for your fast group, and check the WorkSafe page for the current wording.
5. Can casual workers help with a re-slot?
Yes. A re-slot is a good job for a small group of casual or labour hire hands working under one leader, because the task is defined and short. Give them the plan, a briefing on the putaway rules and a site induction first, and have the leader check the record at the end of each shift.
Move the lines, shorten the walk
Warehouse slotting does not need new racking or new software. It needs a month of pick records, a ranking, a plan that puts fast lines close to dispatch and in the easy height band, and putaway rules the crew actually follow. Run the move in a quiet week under one leader and record every change the same day. This week, export last month's picks and rank your ten most picked lines.
