How Better Scheduling Frees the Cash Trapped in WIP

Work in process is cash you have already spent standing on the shop floor, and most of it is put there by release timing, not by how fast anyone works. A job started three days before its next machine is free does not ship three days sooner: it becomes three days of paid-for inventory waiting in a queue. EDGEBIC by User Solutions frees that cash by computing each job's start date from real downstream capacity, so material stays as raw stock or in the bank until the floor can genuinely absorb it.

This post names the mechanisms that move working capital, shows the arithmetic on documented worked examples, and is honest about the risk you accept when you carry less. For the metric itself, see the cash conversion cycle glossary and WIP inventory. This post sits under the EDGEBIC results guide, and it is the money-flow companion to how EDGEBIC reduces work in process, which covers the floor-congestion side of the same lever.

Why WIP Is Cash, Not Just Clutter

Trace one job through your ledger. You buy the steel: cash out. You issue it to the floor and burn setup and run hours on it: more cash out. Until that job ships and you invoice it, none of that money has come back. It is sitting on the floor wearing the shape of a half-finished part.

The cash conversion cycle measures exactly this: the days between paying your supplier and collecting from your customer. Work in process is a large, controllable chunk of those days. Every day a job spends waiting in a queue is a day your money is locked up, and the balance sheet counts that locked money as inventory rather than the cash it used to be.

The important word is controllable. A pile of half-finished jobs feels like an operations problem, but the cash it represents was committed by a scheduling decision: when to release the material. Change the decision and you change the cash.

Where the Trapped Cash Comes From

Three sources, in rough order of size in a typical job shop:

1. Early release. Material issued before the routing can absorb it. The job exists, ties up cash, and moves nowhere.
2. Full-lot waiting. A downstream station waiting for all 200 pieces when it needs the first 20. The whole lot is trapped cash for the length of the upstream run.
3. Queue behind genuine contention. Jobs stacked in front of a machine that is truly busy. This is the honest kind, and the only one that shrinks by adding capacity or improving sequence rather than by changing release timing.

Scheduling has a direct mechanism for the first two and a partial one for the third. None of them ask anyone on the floor to work faster.

Mechanism One: Start Late on Purpose

Forward scheduling starts every job as early as it can and piles the slack at the end. That is the safe choice and the expensive one, because the slack is paid for in material standing on the floor.

Backward scheduling inverts it. The engine places the last operation to end at the due date, then works upstream in reverse, right-aligning each step against the deadline its successor imposes. The slack lands in front of the job, where it costs nothing.

The documented worked example, 40 valve bodies through a three-step routing, makes the cash visible:

The order can start as early as Monday July 6. Backward scheduled, it starts Thursday July 9, and it is still delivery-ready on its due date. Three days of slack move from behind the job to in front of it. For those three days the material stays in the stockroom, off the WIP line, and out of the cash conversion cycle.

Now price it. Say this valve body carries 800 dollars of material and issued labor by the time it starts. Holding three days of early release off the floor is three days that 800 dollars stays liquid. One order is small. The number that matters is the sum across every order in your book that starts as early as possible out of habit rather than need. If a hundred active jobs each release two days early against an average committed value of 800 dollars, that is 160,000 dollars of material continuously on the floor that did not have to be there yet.

Mechanism Two: Stop Financing the Whole Lot

The second source is a lot sitting complete at one station because the next station is waiting for all of it.

Lot streaming breaks the wait. The downstream step starts once a transfer batch has accumulated, using the documented formula: setup, plus the smaller of transfer batch and order quantity, times hours per piece.

The worked case: 100 shafts, half an hour of turning per piece, two hours of setup, a transfer batch of 20 pieces, half an hour of handling delay. Drilling starts 12.5 hours into a 52-hour turning run rather than at the end. The elapsed time compresses from 52 hours to about 37, but the cash effect is separate and blunt: the shafts stop stacking up as finished-at-turning-and-waiting inventory, because pieces flow forward while turning continues. The lot is never fully trapped at one station.

Mechanism Three: Do Not Finance What You Already Own

The cheapest work in process is the job that never enters the floor. Where a finished item is stocked, EDGEBIC can net demand against on-hand balance and build only the shortfall. See how EDGEBIC nets demand against stock.

The documented netting case: 80 units on hand, a 60-unit order, and a 30-unit order behind it. The 60-unit order is covered entirely from stock and never becomes a scheduled job. The 30-unit order draws the remaining 20 and manufactures only the 10-unit balance. Two orders on the books; one produced zero work in process because it produced zero work.

The Cash Picture, Assembled

Put the three mechanisms together on a single quarter and the arithmetic is additive, not magical. Backward scheduling holds early-release material off the floor. Lot streaming stops whole lots from pooling as trapped inventory between stations. Netting keeps covered orders from ever consuming cash. Each is a specific instance of the same rule: material becomes work in process only when the schedule genuinely needs it to, and cash stays liquid until then.

None of this changes your throughput, which is the point that makes it a clean win. The floor produces the same hours. It simply produces them while financing less standing inventory, and the difference lands as working capital you can see on the balance sheet.

What the Software Cannot Do Alone

Three honest limits keep this from being a slide-deck promise.

It cannot rewrite your supplier terms. Scheduling controls when material moves onto the floor, not when you pay for it or how long lead times run. If you pay 30 days before the earliest possible release anyway, holding release later frees floor cash but not necessarily purchase cash. The cash conversion cycle has three parts, and scheduling moves one of them.

Less WIP is less buffer. Backward scheduling deliberately removes downstream slack, so a disruption immediately threatens the promise. EDGEBIC treats backward as opt-in per order with automatic fallback to forward when the just-in-time plan cannot hold, but the decision of which jobs can safely run lean is a business judgment about risk, not a setting. Jobs where a late ship is unacceptable should keep their protective runway and their trapped cash.

Lot streaming trades cash for moves. Moving a transfer batch instead of a whole lot means more material handling. The one-piece extreme is documented (50 sub-assemblies finishing in about 13.75 hours instead of 18), and it demands continuous handling your people and layout have to actually support. Pick a transfer batch your floor can run, not the theoretical minimum.

The mechanism is real and the arithmetic is yours to run with your own material values and release habits. What scheduling gives you is the ability to see the trapped cash as a computed number and to release it on purpose, one start date at a time. To put dollars on the whole set of results, start from the EDGEBIC results guide; to see EDGEBIC end to end, visit the product page.