7 Common Mistakes When Conducting Industrial Time Studies (and How to Avoid Them with Software)

Introduction

Industrial time studies and motion analysis are incredibly powerful tools for understanding and improving operational efficiency. When executed correctly, they provide the foundation for optimizing processes, calculating costs accurately, and planning production effectively. However, as with any technical discipline, “the devil is in the details.” The precision and reliability of a Standard Time critically depend on the rigor with which the study is conducted.

Even experienced analysts can fall, sometimes unknowingly, into certain methodological traps. These errors in industrial time studies can completely invalidate the results, leading to management decisions based on incorrect data and generating distrust in the process. This article identifies 7 of the most frequent errors and, more importantly, offers practical advice on how to avoid mistakes in industrial time studies. Additionally, we will highlight how the use of modern time study software can become a fundamental ally in mitigating many of these risks.

The 7 Deadly Sins of Time Studies (and Their Solutions)

Error 1: Measuring a Non-Standardized or Poorly Defined Method

• The Problem: Timing a task without first having defined, documented, and trained a standard and consistent work method. If each operator performs the task differently, or if the same operator varies their method in each cycle, what are we really measuring?
• The Consequence: The observed times will be highly variable and inconsistent, making it impossible to calculate a meaningful Standard Time. Any derived standard will be useless for planning, costing, or performance comparison. It generates frustration and wastes time.
• How to Avoid It: The golden rule: Standardize BEFORE timing! Invest time in observing, analyzing (perhaps with a preliminary motion study), optimizing, and documenting the best known method. Ensure that the operator is trained and follows that standard method during the study.
• How Software Helps: Good time study software allows attaching or linking standard method documentation (descriptions, diagrams, photos, videos) directly to the study, ensuring that the analyst has the correct reference and documenting which method is being measured.

Error 2: Poor Definition of Work Elements

• The Problem: Incorrectly breaking down the task into its constituent elements. Typical errors include elements that are too long (grouping heterogeneous actions), too short (difficult to measure accurately), or with ambiguous or difficult-to-consistently-observe start and end points (“breakpoints”).
• The Consequence: Imprecise elemental times. Difficulty identifying which specific part of the cycle is inefficient. Inability to reuse elemental times to build reliable standard data.
• How to Avoid It: Follow decomposition rules: separate manual elements from machine elements, constants from variables, regular from irregular. Ensure clear and perceptible breakpoints (auditory or visual). Seek a balance in duration (neither too short nor too long).
• How Software Helps: Study templates within the software can guide the analyst to define elements in a structured and consistent manner. Storing standard element definitions facilitates their reuse and coherence across different studies.

Error 3: Insufficient Sampling (Observing Too Few Cycles)

• The Problem: Conducting the time study during a very limited number of work cycles, without taking into account the natural variability inherent in any human or industrial process.
• The Consequence: The average observed time for each element may not be statistically representative of normal long-term performance. The resulting Standard Time will have an unknown and probably high margin of error, making it unreliable.
• How to Avoid It: Don’t rely on generic “rule of thumb” approaches (e.g., “measure 10 cycles”). Calculate the number of necessary cycles using statistical formulas that consider the variability of preliminary measurements, the desired confidence level (e.g., 95%), and the acceptable margin of error (e.g., ±5%).
• How Software Helps: Some software packages can perform these statistical calculations automatically as data is collected, indicating to the analyst how many more cycles are needed to achieve the desired precision, or at least facilitate subsequent calculation.

Error 4: Subjective or Inconsistent Performance Rating

• The Problem: Performance rating (judging the operator’s speed/effort relative to the normal 100% pace) is the most subjective part and, therefore, one of the biggest sources of errors in industrial time studies. Lack of training, analyst fatigue, unconscious biases, or the “halo effect” (rating all elements the same based on the general impression) can lead to incorrect ratings.
• The Consequence: An error in rating directly distorts the Basic Time and, therefore, the final Standard Time, making it too “tight” or too “loose.” It generates distrust in the standards.
• How to Avoid It: Training, training, and calibration! Analysts should receive rigorous training and participate in periodic calibration sessions (e.g., rating reference videos) to ensure consistency. It is advisable to rate element by element if the duration allows. Be aware of possible biases.
• How Software Helps: Although the software does not perform the rating (it remains human), it does ensure that the rating entered by the analyst is clearly recorded for each element or cycle and is consistently and automatically applied in the Basic Time calculations, avoiding subsequent mathematical errors.

Error 5: Reading, Recording, and Manual Calculation Errors

• The Problem: Human errors when reading the stopwatch (especially analog ones), parallax errors, time loss when operating the stopwatch (in the snapback method), and above all, errors when manually transcribing hundreds of readings to a spreadsheet and performing subsequent calculations (averages, basic time, standard time).
• The Consequence: Introduction of incorrect data at the foundation of the study, arithmetic errors that invalidate the final result. Slow and tedious process.
• How to Avoid It: Use digital stopwatches. Prefer the continuous method to avoid losses in resetting. Maximum attention in transcription (double-check). Automate calculations with well-designed spreadsheets.
• How Software Helps: This is an area where time study software offers a decisive advantage. Time capture is digital (a click or tap), eliminating reading and transcription errors. All calculations (elemental times by difference, averages, application of rating, calculation of allowances, final ST) are performed automatically, eliminating mathematical errors and saving a lot of time.

Error 6: Incorrect or Unjustified Application of Allowances

• The Problem: Adding allowance percentages (for fatigue, personal needs, etc.) arbitrarily (“we always use 15%”), without analyzing the specific demands of the task or without basing it on recognized tables (e.g., ILO) or documented company policies. The error of omitting necessary allowances can also occur.
• The Consequence: A final Standard Time that does not realistically reflect the total time needed to perform the task sustainably. It can be unfair to the worker (too tight) or to the company (too loose).
• How to Avoid It: Analyze the task to determine appropriate allowances according to factors such as physical effort, posture, mental stress, environmental conditions, monotony. Use standard tables as a guide and clearly document the justification for the percentages applied. Follow company policies if they exist.
• How Software Helps: The software can include standard allowance databases (configurable according to company policies) and apply them automatically and consistently once the relevant factors are selected. This ensures uniformity and leaves a clear record of which allowances were applied and why.

Error 7: Poor Communication and Lack of Environment Preparation

• The Problem: Approaching the study without adequate prior communication with the operator (not explaining the purpose, generating anxiety or suspicion) or without verifying that the workstation is prepared according to the standard method (missing tools, poorly located materials, abnormal conditions).
• The Consequence: The operator may work at an unnatural pace (faster or slower due to nerves), avoidable interruptions may occur, time is lost in preparing the workstation during the study. The collected data will not be representative, and the trust relationship is damaged.
• How to Avoid It: Transparent, honest, and early communication is key. Explain the “why” and the “how.” Ensure cooperation. Before starting to measure, perform a final check to confirm that the workstation, tools, and materials comply with the defined standard method.
• How Software Helps: While communication is human, software helps to have all relevant information (method, conditions, tools) documented and easily accessible for preparation and prior verification, ensuring that measurement occurs under the correct conditions.

Software as a Protective Shield Against Errors

As we have seen, dedicated time study software does not eliminate the need for good methodology and a well-trained analyst, but it does act as a powerful shield against many of the most common and costly errors, especially those related to:

• Measurement Precision: Eliminates errors in reading and recording times.
• Calculation Accuracy: Automates additions, subtractions, averages, application of ratings and allowances, eliminating human errors.
• Consistency: Ensures that allowances and calculation methods are applied uniformly.
• Documentation: Centralizes and standardizes study information (method, elements, times, ratings, allowances, results).
• Efficiency: Drastically accelerates the post-measurement analysis and calculation process.
• Analysis: Facilitates statistical analyses (variability, sample size) and comparison between studies.

Conclusion

The reliability of Standard Times is the cornerstone of their utility. Making errors in industrial time studies not only wastes the time invested in the study but can also lead to harmful business decisions. Knowing these 7 common errors is the first step to preventing them.

Rigorous application of methodology, solid training (especially in performance rating), and transparent communication are essential to knowing how to avoid mistakes in industrial time studies. However, in the current environment, relying on modern time study software is an intelligent strategy to significantly minimize the risks of measurement, calculation, and consistency errors, allowing analysts to focus on observation and method improvement. Review your current processes, identify possible weak points, and consider how technology can help you achieve more accurate, reliable, and efficient time studies.

Additional Resources

To implement an effective industrial time study system that minimizes these common errors, CRONOMETRAS offers an advanced technological solution specifically designed for time studies. Our application facilitates the entire process, from element definition and time capture to performance rating, application of allowances, and generation of detailed reports.

Request a free demo to discover how CRONOMETRAS can help you avoid these common errors and improve the accuracy and reliability of your time studies.