WIP Tracking: Best Practices for Managing Work in Progress

Throughout the course of typical operations, manufacturers will generally have products in various stages of completion. This is especially true for manufacturers of large, complex, and time-consuming products such as machinery and other industrial equipment. Products that have yet to be completed are typically referred to as Work in Progress (WIP).

In order for businesses to be able to properly track production across their supply chain through distribution, it’s imperative that they understand how many products they have across the varying stages of completion.

In this post, we’ll review the concept of Work in Progress and why it’s important for manufacturers to keep track of WIP within their operations.

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Work in Progress is a term used by manufacturers to describe items that have started the production process, but have not yet been completed. The important thing to note is that work in progress is about more than goods and orders awaiting fulfillment. The concept is also used to describe costs associated with the work involved in completing the remaining steps of the production process.

Therefore, work in progress refers to materials still within the production process plus labor, overhead, and related production expenses. These expenses point to the total manufacturing cost sunk into finishing the products necessary to complete an order.

Managing and reducing work in progress is essential for manufacturing businesses because it can significantly impact the overall efficiency of production. Therefore, proper work in progress management provides many benefits for manufacturing businesses. Some of the main benefits include:

Improved inventory planning and management: Determining the amount of work in progress shows manufacturers the state of their order fulfillment efforts and resource utilization. This allows manufacturers to order raw materials from suppliers only as needed, making inventory management and planning much simpler.

Better productivity and production efficiency: When businesses examine their manufacturing operation and notice an unexpectedly large amount of work in progress, it points to an inefficient production process. Higher than expected WIP indicates that there might be bottlenecks along the production line, leading to a build-up of unfinished goods. Effectively managing work in progress allows businesses to assess their production processes and refine operations to increase efficiency.

Increased customer satisfaction: With the increased production efficiency, manufacturers can more consistently meet demand and fulfill customers' orders on time. Ensuring that orders are completed on time is a significant factor contributing to customer satisfaction.

Improved warehouse management: Knowing the amount of work in progress allows manufacturers to assess their warehouse usage and storage needs. This reveals if the space contains more work in progress than required, preventing waste of both materials and space.

At the core of every efficient production system sits a deceptively simple equation with major consequences: Little’s Law.

If you’ve ever wondered why work stacks up or why output lags even when everyone’s busy, this formula gives you the answer.

Little’s Law: W = L / λ

Where:

• W = Average number of items in the system (Work in Progress)
  
  

• L = Average lead time (how long it takes to complete a unit)
  
  

• λ = Average throughput rate (units completed per time period)
  
  

Put plainly: to shorten lead time, you either increase throughput or reduce WIP. That’s the whole story. No advanced math needed.

A Practical Example

Picture a line producing 10 units per hour (λ = 10) with 50 units in progress (W = 50).
Using Little’s Law:

L = W / λ = 50 / 10 = 5 hours

So the average item takes 5 hours to travel through the system.

Now, say you cut WIP in half without changing throughput:

L = 25 / 10 = 2.5 hours

Lead time drops by half i.e. without new equipment, overtime, or major process changes. Just tighter control of what’s in progress.

That’s why Little’s Law is a cornerstone of lean manufacturing. It links broad goals like faster delivery to practical actions like limiting WIP.

Why It Matters

Most plants run with more WIP than they think. And excess WIP slows everything down.

Queues get longer.
Changeovers stretch out.
Defects hide in the pile.

By using Little’s Law, teams can see how flow, inventory, and output interact—and make better calls on where to adjust.

You can’t manage WIP alone. The numbers tell the story. When tracked regularly, they reveal where flow slows, where work backs up, and where time quietly disappears.

Here are the four that matter most:

What to Watch

If cycle time stretches out but throughput doesn’t budge, you’re likely stacking inventory between steps.
If one area always shows more WIP than the rest, that’s your bottleneck.
And if flow efficiency is buried in the single digits, most of your process time is being spent waiting rather than producing.

These numbers are more than reports for the wall. They describe how your system behaves on a normal day. Track them long enough and you’ll start to see patterns e.g. where time leaks, which products stall, and which shifts keep things moving.

You don’t need a full-scale system overhaul to get WIP under control. What you do need is consistency, visibility, and a team that sticks to simple rules every day. The plants that manage flow best tend to share a few habits.

1. Set WIP Limits by Station
Decide how much work can sit at each step before the next one starts. Those limits keep the line from clogging and make bottlenecks obvious. A good starting point is your current average, then fine-tune as you see how work actually moves.

2. Make Queues Visible
If people can’t see the queue, they can’t manage it. Put WIP counts where everyone can spot them, whether that’s on a physical board, a tablet display, or a shared dashboard. Real-time visibility keeps supervisors and operators aligned without chasing updates.

3. Track Blockers, Don’t Just Push Through Them
Every time work stalls, record why. Missing parts, a tool down, a late approval - whatever it is. Once those reasons are visible, patterns emerge. You’ll find a few recurring causes that create most of the lost time.

4. Capture Data Automatically
Handwritten counts and manual updates always lag behind reality. Connect machines, scanners, or basic sensors to log WIP movement automatically. It saves time, keeps data clean, and shows exactly where things slow down.

5. Keep Tuning the System
WIP limits aren’t permanent. As you track cycle time, throughput, and flow efficiency, test small changes. Maybe a slightly lower limit speeds things up, or a layout tweak cuts wait time. The key is to adjust often and base changes on what the numbers actually show.

Maintaining a high level of work in progress shows inefficiency in the entire production process. In addition, a high WIP indicates that a significant amount of capital is tied up within the business, leading to constrained cash flow and fewer profits.

In the modern manufacturing scene, businesses should leverage their enterprise resource planning systems (ERP), manufacturing execution systems (MES), and other manufacturing systems to manage work in progress.

Here’s how to properly track and manage work in progress:

Adopt just-in-time manufacturing: Manufacturers should apply the pull system in just-in-time manufacturing. Leveraging this lean technique ensures that production doesn’t start until after order placement by customers.

Just-in-time ensures no excess work in progress is lingering across the warehouse or production lines to tie up resources. Instead, materials are processed and turned into final products if and when there’s direct demand from a client.

Analyze and forecast demand accurately: In some operations, manufacturers will opt to run a push system rather than a pull system because their offerings have extended demand from the market. As a result, these businesses always have work in progress to meet the continuous, regular demand.

But since errors in forecasting or unexpected lulls in demand can happen, such manufacturers are often left with a high level of WIP. Utilizing advanced forecasting solutions to analyze the market gives manufacturers a more representative picture of market forces, enabling smoother workflow on the production line.

In demand shortfalls, these push system manufacturers should leverage event-driven dispatching systems on the shop floor. These systems optimize production on the line, adjusting production volume appropriately to respond to the changes in demand.

Upgrade machinery and personnel: In many instances, increased WIP results from bottlenecks within the operations. A viable solution is upgrading tools and machinery that can process work quicker and more efficiently.

Additionally, the personnel at the station might not be equipped to handle the workflow, resulting in additional bottlenecks and WIP. Extra training and skilling can make workers more competent in dealing with increased WIP at their stations. Alternatively, manufacturers can opt to hire better trained and more experienced operators.

In order to better manage work in progress, manufacturers must leverage the data collected by their ERP, MES, and other production systems to reduce bottlenecks and optimize manufacturing workflow on the shop floor.

While the implementation of digital solutions to help collect data and track production is often perceived as time and resource-intensive, the benefits far outweigh these initial upfront costs.

Some of the benefits of digitizing WIP management include:

• Typically, the systems that are implemented within a manufacturing environment collect data automatically, eliminating human error, a significant cause of WIP.

• Digital, data-driven process controls can adequately handle much of the production line, leaving personnel to execute tasks that require more cognitive power.

• The insights generated by WIP management tools often promote continuous improvement within a manufacturing environment by identifying points of inefficiency on a regular basis and enabling supervisors to issue corrective actions.

• Well-integrated systems and equipment combined with predictive analytics can identify a possible occurrence of bottlenecks, enabling workers to intervene before WIP piles up.

By connecting the people machines, and systems across a manufacturing environment, Tulip has the ability to automate data collection across an entire operation. Using the insights that Tulip provides, manufacturers are able to more effectively plan and forecast their production needs, tackling the root cause associated with unmanageable WIP.

Even with solid systems and good intentions, WIP control can slip off track. These are the traps most teams hit and some ways to keep clear of them.

1. Setting Limits Too Tight
WIP limits keep flow under control, but if you squeeze them too hard, the line starts starving. Work stalls, operators wait, and throughput falls.
How to handle it:
Start with numbers that reflect real cycle times and capacity. Watch how often stations hit their limit. If upstream queues grow or downstream utilization drops, loosen it a bit.

2. Chasing Symptoms Instead of Bottlenecks
Extra WIP almost always gathers where flow slows down. The problem is that teams often focus on the visible backup rather than the real constraint.
How to handle it:
Review WIP by stage and track flow efficiency. If one area stays heavy while others run light, that’s the bottleneck. Fixing that spot usually lifts the entire line.

3. Losing Operator Engagement
Digital tracking falls apart when it feels like extra paperwork. If the system slows people down or doesn’t seem useful, it won’t get used and your data turns unreliable.
How to handle it:
Bring operators in early. Explain how better visibility makes their day smoother with fewer surprises, fewer fire drills. Keep inputs simple, automate when possible, and build tools that fit how people actually work.

Manual WIP tracking works for a while. A whiteboard or shared spreadsheet can keep a small line in sync. But once volume grows or work crosses shifts, things start slipping. Numbers go stale, updates lag, and nobody’s quite sure what’s current.

Tulip helps close that gap. It gives engineers and supervisors tools to build their own digital tracking systems without waiting on software teams. In practice, that means you can:

• Record work orders automatically as they move through each station

• See queues and flow on live dashboards that update themselves

• Log cycle times, blockers, and statuses at the moment they happen

• Pull data directly from machines, scanners, or tablets

Because the system runs in the cloud, it’s easy to roll out across multiple lines and tweak as processes change. No long projects, no IT bottlenecks.

That’s the real gain: fewer surprises, quicker adjustments, and a floor that runs on facts instead of guesses.

Manual vs. Automated WIP Tracking

Digital tracking doesn’t just make reports look cleaner. It changes how people manage the floor. When the data updates itself, operators and supervisors can focus on running the process instead of chasing numbers.

By connecting the people, machines, and systems across a manufacturing environment, Tulip has the ability to automate data collection across an entire operation. Using the insights that Tulip provides, manufacturers are able to more effectively plan and forecast their production needs, tackling the root cause associated with unmanageable WIP.

Work in progress isn’t just a number on a report. It shows how your system really behaves. When there’s too much of it, parts sit, queues grow, and everything feels slower than it should. When there’s too little, stations start running dry and people wait for work. Getting that balance right depends on how clearly you can see what’s happening and how fast you react.

Simple principles like Little’s Law, help make sense of it. The right metrics keep you honest about where time and material are stuck. Day-to-day discipline keeps things from drifting back to chaos.

And when you’re ready to get past manual counts and spreadsheet updates, a platform like Tulip can take care of the tracking. It gives you live data straight from the floor so you can focus on fixing flow, not collecting numbers.

If you’re interested in learning how Tulip can help make your production processes more efficient, reach out to a member of our team today!