Lean Laboratory Principles helps to minimize weighing errors. Download the First-Defect-Stop Guide.

Minimize Weighing Errors using Lean Laboratory Principles


With a First-Defect-Stop Procedure

Minimize weighing errors with a Lean Laboratory Principles
Minimize weighing errors with a Lean Laboratory Principles

Lean Laboratory principles are increasingly being applied to the laboratory environment, with the aim of increasing quality and efficiency. One important aspect is "Jidoka", a Japanese Lean Manufacturing term, which means empowering machines or operators to stop production automatically on discovery of a defect in a process. Applying this Lean Laboratory principles involves:

  • Stop a process as soon as a problem is detected (to avoid propagating errors through the workflow)
  • Fix the problem quickly (to avoid delays)
  • Investigate the root cause of the problem
  • Take steps to avoid any reoccurrence of the same problem

If a problem is detected, the "First-Defect-Stop"  procedure should be triggered. The aim of First-Defect-Stop is to enable a laboratory technician to stop the process, identify a problem and resolve it within 10 minutes (e.g. using a checklist). If the problem cannot be resolved quickly or easily, they should escalate the issue (e.g. notify supervisor or 3rd party service provider).

The ultimate goal, of course, is not only to solve the problem once, but to address the cause and eliminate it, in order to prevent the error recurring. Repeatedly ignoring the root cause of the problem is foolhardy, because it simply leads to inefficiency and further errors downstream, causing inaccurate results, poor reproducibility and extended lead times.


This First-Defect-Stop guide is a trouble-shooting tool designed to help you identify specific problems with your laboratory balance, such as long settling times or unstable readings. Then analyze the root causes, which may be caused by the environment, the sample, the method, the user, or the equipment. It also gives advice on steps that can be taken to prevent this problem from happening again, with step-by-step lean laboratory principles guidance to help you:

1.     Identify the problem

2.     Install warnings (Andon)

3.     Assess the problem

4.     Reduce the impact

5.     Analyze the cause(s)

6.     Avoid in the future


Download your free guide today and address any weighing errors in your lab by following lean laboratory principles!

"Andon", another Japanese Lean Manufacturing term, is a visual signal or system designed to alert staff of a quality or process problem. This problem visualization method can also be implemented in the laboratory. For example, the latest generation of METTLER TOLEDO balances (XPR and XPE series) include a Status Light function which supports this principle.

3. Optimum Location: Workplace Preparation
3.1. Identify the Problem
3.2 Install Warnings
  • Use a temperature sensor
  • Turbulent air flow with air speed > 0.3 m/s
3.5 Analysis of Causes
  • Control effects of the air-conditioning system
  • Close windows before weighing
  • Check ventilation system in a safety cabinet (turbulence)
3.3 Problem Assessment
  • Ideal temperature is 20 °C for the air-conditioning
  • Weighing doors are open during weighing
  • Air drafts > 0.5 m/sec
3.6 Avoiding in the Future
  • Use a draft shield
  • Use weighing accessories such as SmartGrid, SmartPan
  • Optimize weighing filters settings
3.4 Reduce Impact
  • Ensure a stable temperature in the lab, between 20 °C and 24 °C
  • Close doors (or use sliding doors) and close windows
  • Reduce air drafts
9. Weighing Workflow: Adjustment
9.1 Identify the Problem:
9.2 Install Warnings
  • Activate internal adjustment functions like FACT
  • Use the StatusLight warning system
  • Settling time takes > 60 sec.
9.5 Analysis of Causes
  • All balances will drift over time, if there  is no adjustment procedure
9.3 Problem Assessment
  • Balance is inaccurate
  • Display digits show an implausible value
9.6 Avoiding in the Future
  • Use a balance with the FACT safety function
  • Integrate the balance routine testing procedure into your SOP if there is no auto-adjustment feature
9.4 Reduce Impact
  • Adjust the sensitivity regularly
  • Enable the internal adjustment weight(s)