Comparing Process Analyses: Motion-Mining®, REFA & MTM (Part 1)

Introduction: Why a Comparison of Methods is relevant

Today, intralogistics is under unprecedented pressure to optimize. The ongoing shortage of skilled workers is hitting volatile supply chains, while operating costs are rising and customer demands for delivery speed and flexibility are increasing. Companies must do more with fewer resources. An equation that can only be achieved by systematically increasing efficiency.

Paradoxically, businesses now have more data and technology options available to them than ever before. Sensors, wearables, warehouse management systems, and camera tools continuously generate information about every process step. But this is exactly where the dilemma lies: The operational constraints of day-to-day business rarely leave room for in-depth analyses. While IT systems collect millions of data points, there is often a lack of time, expertise and methodological competence to gain actionable insights from them. The result is a reactive optimization approach. Problems are solved selectively when they become acute. Improvement measures are based on the obvious, not on the most potential. Ad-hoc decisions replace data-driven strategies. This approach may provide relief in the short term, but it systematically wastes potential for improvement and ties up more resources than necessary in the long term.

At the same time, the available analysis methods have evolved. In addition to established methods of work science such as REFA and MTM, which have been tried and tested in industrial practice for decades, digital approaches such as Motion-Mining® are increasingly appearing on the screen. These promise faster data collection, lower analysis costs and objective process illustrations. But under which conditions, which method actually provides the answers you need?

For decision makers in intralogistics, production/manufacturing and retail logistics, the choice of method is therefore a strategic question. The wrong analysis method can tie up significant resources without providing the insights you're hoping for. Conversely, the right method at the right location enables measurable improvements in throughput times, workload and process quality.

The aim of this blog post is to bring clarity to this decision-making situation. It provides a well-founded orientation between the three central approaches REFA, MTM and Motion-Mining® and shows their respective strengths, limits and typical application scenarios. It does not provide a general recommendation, but a pragmatic decision-making aid: Which method fits under which framework conditions? Which requirements must be met? And when is which analysis effort actually worthwhile?
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2. Overview of Methods

2.1 REFA: Structured process analysis and time studies

For decades, REFA has been synonymous with systematic work science in practice. The abbreviation originally stood for “Reich Committee for Working Time Determination” and today describes a comprehensive set of methods for work data collection and process design. In essence, REFA is based on the direct observation of work processes by trained specialists who use standardized procedures to record time data, document process structures and identify optimization potential.

The methodological basis is the precise division of work processes into individual process stages, the time required for which is systematically measured. Various survey techniques are used: time recordings with a stopwatch or digital recording devices for repetitive activities, multi-moment studies for statistical recording of distribution times and process analyses for process visualization. These are supplemented by value stream analyses, which make the flow of materials and information transparent across entire process chains.

The strengths of the REFA methodology lie in its broad establishment and methodological maturity. The standards have grown over decades, tried and tested in countless practical applications and enjoy a high level of acceptance by both management and works councils. Context sensitivity is particularly valuable: REFA practitioners are directly involved in the process, can identify specific situational features, identify disorders and explore causes in dialogue with employees. This qualitative component makes it possible not only to measure times, but also to understand relationships.

For intralogistics, REFA provides a solid basis for creating process transparency and redesigning work organization. Processes can be systematically structured, waste becomes visible, and improvement measures can be based on reliable data. The method is particularly effective in areas with manageable complexity and easily observable activities.

The limitations of REFA result from the manual nature of data collection. Time studies and observations are personnel and time-consuming. Depending on the complexity of the research area, analyses can take several weeks. The presence of observers in the work area can also disrupt operations and trigger reactivity effects. Employees may behave differently under observation than in normal working life (Hawthorne effect). This subjectivity risk affects both the observed and the observers themselves, whose perception and evaluation is subject to individual influences.

The use of REFA is particularly challenging when larger areas or several locations are to be analyzed in parallel. Scaling requires suitably trained personnel and data consolidation across various investigations is complex. In highly dynamic environments with highly variable process flows, classic time studies also reach methodological limits, as they are based on a sufficiently large sample of repeatable processes.

Typical applications for REFA can be found wherever manual activities with clear process sequences dominate. In assembly, the method enables precise target/actual comparisons of cycle times and forms the basis for line balancing. In order picking, travel times, gripping processes and set-up times can be recorded and optimized in detail. REFA also provides the methodological basis for well-founded decisions when redesigning workplaces or introducing changed processes.

REFA is particularly suitable as an introduction to systematic process analytics for companies with an even low level of digitization. The method requires no IT infrastructure and can be implemented with manageable technical effort. Especially in medium-sized companies, where process documentation and time data have so far been lacking, REFA creates the necessary transparency and lays the foundation for continuous improvement.
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2.2 MTM: Precise time calculation using standardized movement components

MTM (Methods-Time Measurement) follows a fundamentally different approach than the observation-based REFA methodology. Instead of measuring work processes directly at the workplace, MTM breaks down every manual activity into its elementary basic movements and determines the time required from predefined, scientifically validated time components. Every human movement, whether it is grasping, transporting, positioning, releasing or pressing, is analyzed in accordance with standardized rules and provided with a time value.

The method is based on extensive empirical research from the 1940s, which have systematically recorded how long people need for specific movements under normal conditions. These time values are stored in detailed tables and take into account relevant influencing factors such as distances, weights, positioning accuracies or movement complexity. An MTM analyst can theoretically penetrate a work process without having to physically observe it — provided that the process is precisely described or visualized.

MTM's strengths lie in the exceptional accuracy and objectivity of time calculation. Since the method is based on standardized components, results can be directly compared across different workplaces, locations and points in time. Subjective observer effects are largely eliminated and the reproducibility of the analyses is very high. This makes MTM particularly valuable for precise workplace design and the development of optimized work processes already in the planning phase, long before a line is set up or a process is implemented. For intralogistics, MTM offers considerable added value in the systematic optimization of manual processes. The method not only supports pure time calculation, but also enables well-founded ergonomic assessments. Unfavorable movement patterns, stressful postures or inefficient gripping routes can be identified and eliminated as early as the planning stage. MTM also provides a robust basis for standardization initiatives, cost calculation and the definition of realistic performance requirements. Especially in series processes with high repetition rates, the analysis effort pays off through precise cycle coordination and optimal resource utilization.

The limitations of MTM result from methodological complexity and the required level of specialization. The application of the method requires comprehensive training. MTM analysts go through intensive training programs to correctly identify, classify and apply the movement components. Building up this methodological expertise requires time and resources, and not every company is able to provide appropriate know-how internally. Carrying out an MTM analysis is also time-consuming. Each process must be dismantled in detail, and every movement must be individually analyzed and documented. For complex tasks with many process variants, this can take several days. In addition, the method shows its strengths particularly in standardized, repeatable processes. In highly variable or unstructured work environments, where activities are highly dependent on the situation or have to be improvised frequently, MTM reaches practical limits. Modelling such processes would require a disproportionate amount of effort without providing corresponding insights.

Typical applications for MTM are primarily in series production and in highly standardized manual activities. In the assembly of consumer goods, electronic components or automotive parts, the method enables precise cycle and line optimization. Manual workstations can be analysed down to the last detail and optimised in terms of movement economy. When planning new production lines or redesigning existing areas, different layout variants can be systematically compared without having to build physical prototypes.

In intralogistics, MTM is particularly used for repetitive picking or packaging processes, where significant increases in productivity can be achieved through optimised movement sequences and ergonomic workplace design. MTM also provides an objective, comprehensible basis for defining time limits and performance levels, which can be used in works agreements or remuneration systems. MTM delivers its full value wherever detailed ergonomics and movement analyses are required, for example when designing age-appropriate workplaces or preventing stress-related diseases.

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