Ergonomic indicators

Product quality indicators

VI.1.1 VI.2.1

VI.1.2 VI.2.2

VI.1.3 VI.2.3

VI.1.4

VII.1

VII.2

VII.3

VIII.1

VIII.2

VIII.3

Rice. 1. Classification of quality indicators

Figure 1 shows the classification of quality indicators according to the following criteria:

I – by the number of characterizing properties

I.1 – complex, I.2 – single;

II – according to the way of expression

II.1 – in natural units; II.2 – in relative units; II.3 – in points; II.4 – specific;

III – in importance:

III.1 – main (including main ones); III.2 – auxiliary (additional);

IV – according to the stage of determination

IV.1 – predictive; IV.2 – design; IV.3 – production; IV.4 – operational;

V – by areas of analysis:

V.1 – technical; V.2 – economic; V.3 – technical and economic;

VI – according to the method of determination:

VI.1 – according to the method of obtaining information:

VI.1.1 – measurable; VI.1.2 – calculated; VI.1.3 – registered by counting discrete objects; VI.1.4 – organoleptic;

VI.2 – by source of information:

VI.2.1 – expert; VI.2.2 – sociological; VI.2.3 – traditional.

VII – according to the application for level assessment:

VII.1 – the products under consideration; VII.2 – basic; VII.3 – levels;

VIII – by area of application:

VIII.1 – to a unit of production; VIII.2 – to a set of units of homogeneous products; VIII.3 – to a set of units of heterogeneous products.

Currently, the following classification of quality indicators used in assessing the quality of products of various types is used, which is shown in Figure 2.

I – destinations:

I.1 – classification; I.2 – functional and technical efficiency; I.3 – constructive; I.4 – composition and structure;

II – reliability:

II.1 – reliability; II.2 – durability; II.3 – storability; II.4 – maintainability;

III – economical use of resources in the application of products:

III.1 – material; III.2 – energy; III.3 – labor;

IV – manufacturability:

IV.1 – technological rationality; IV.2 – material consumption; IV.3 – accuracy and purity; IV.4 – prefabricated; IV.5 – interchangeability; IV.6 – controllability; IV.7 – testability; IV.8 – instrumental accessibility; IV.9 – constructive continuity; IV.10 – applicability; IV.11 – repeatability of parts and assembly units; IV.12 – technological continuity; IV.13 – applicability of technological processes (TP) and technological equipment (STO); IV.14 – repeatability of TP and SRT;

V – ergonomic:

V.1 – hygienic; V.2 – anthropological; V.3 – physiological; V.4 – psychophysiological;

VI – aesthetic:

VI.1 – information expressiveness; VI.2 – rationality of forms; VI.3 – composition integrity; VI.4 – perfection of production performance;

VII – transportability;

VIII – standardization and unification:

VIII.1 – applicability; VIII.2 – repeatability;

IX – patent law:

IX.1 – patent protection; IX.2 – patent protection;

X – ecological;

XI – security.

According to the properties

II.1 I.1

II.2 I.2

II.3 III.1 I.3

II.4 III.2

III.3 I.4

IV.1 IV.9

IV.2 IV.10

IV.3 IV.11

IV.4 IV.12

IV.5 IV.13

IV.6 IV.14

IV.7

IX.1

IV.8

IX.2

V.1

V.2 VI.1 VIII.1

V.3 VI.2 VIII.2

V.4 VI.3

VI.4

Fig.2 Nomenclature of properties according to various classification criteria.

Choice of nomenclature of indicators of quality of industrial production.

When choosing a nomenclature of product quality indicators, a list of names of quantitative characteristics of product properties that are part of product quality and provide an opportunity to assess its quality level is established.

Basic provisions.

The rationale for choosing the nomenclature of quality indicators is carried out taking into account:

– purpose and conditions of use of products;

– analysis of consumer requirements;

– tasks of product quality management;

– composition and structure of the characterized properties;

– basic requirements for product quality indicators.

The procedure for choosing the nomenclature of product quality indicators provides for the definition of:

– type (group) of products;

– purpose of application of the nomenclature of product quality indicators;

– initial nomenclature of product quality indicator groups;

– the initial nomenclature of product quality indicators for each group;

– method of choosing the nomenclature of product quality indicators.

The type (group) of products is established on the basis of intersectoral and sectoral documents that classify products according to their purpose and conditions of use. An intersectoral level document is, for example, the “All-Union Product Classifier (OKP)”.

The objectives of the application of the nomenclature of product quality indicators are set in accordance with the objectives of product quality management.

The initial nomenclature of groups of indicators of product quality is selected using Table 1 of the applicability of indicators below.

Applicability of key quality indicators

by classes and product groups

Table 1

Product quality indicators First class products Second class products
1st group 2nd group 3rd group 1st group 2nd group
Purpose of Reliability Cost-Effectiveness: Reliability Durability Maintainability Persistence Ergonomic Aesthetic Manufacturability Transportability Standardization and Unification Patent Law Environmental Safety + + – – – + – – + + – – + + + + – – + + + + + + – + + + + + – – + + + + + + + + + + + + + + – + + + + + + + + + + + + + + + + + + + + + + + +

The initial nomenclature of product quality indicators for each group of indicators is selected on the basis of regulatory documents for the system of product quality indicators, taking into account the above requirements.

The method for choosing the necessary and sufficient range of product quality indicators is established in the standards and methods for choosing the range of quality indicators.

1.1. Purpose indicators. Purpose indicators characterize the properties of the product, which determine the main functions for which it is intended, and determine the scope of its application.

In the standards for the nomenclature of indicators and in industry methods for assessing the level of product quality, it is necessary to indicate the destination indicators for various conditions of product use. In particular, when assessing the quality level of trucks, the nomenclature of destination indicators will be different for operation in the Far North, in Central European and other regions. When determining the destination indicators, one should choose for analysis, comparison and other operations due to the assessment of the level of product quality, only the most necessary of them, characterizing the most important properties of the product.

The group of indicators of purpose includes the following subgroups:

– classification indicators;

– indicators of functional and technical efficiency;

– constructive indicators;

– indicators of composition and structure.

Classification indicators characterize the belonging of products to a certain classification group. Classification indicators, for example, include: motor power; excavator bucket capacity; gear ratio of the gearbox; tensile strength of cardboard for shoes; carbon content in steel, etc.

Indicators of functional and technical efficiency characterize the beneficial effect of the operation or consumption of products and the progressiveness of technical solutions embedded in products. These indicators for technical objects are called operational.

Functional and technical efficiency indicators include:

– an indicator of the productivity of the machine, which determines the amount of manufactured products for a certain period;

– indicator of accuracy and speed of response of the measuring device;

– an indicator of the strength of the fabric for garments;

– specific energy intensity of an electric fireplace, determined by the consumption of electricity per unit of generated heat:

– an indicator of the waterproofness of the fabric for the raincoat;

– calorie content of food products, etc.

Structural indicators characterize the main design solutions, ease of installation and installation of products, the possibility of its aggregation and interchangeability.

For products for which design documentation has been developed, the use of design indicators in assessing the quality level is mandatory.

Design indicators, for example, include: overall dimensions, connecting dimensions, the presence of additional devices, for example, the presence of a signal and a calendar in a wrist watch, etc.

Indicators of composition and structure characterize the content of chemical elements or structural groups in the product.

Composition and structure indicators, for example, include:

– percentage of components (alloying additives) in steel;

– concentration of various impurities in acids;

– percentage of sulfur, ash in coke;

– the percentage of sugar, salt in foods, etc.

Reliability indicators

Reliability indicators characterize the property of a technical object to continuously maintain operability for some time or some operating time.

Reliability indicators include:

– probability of failure-free operation;

– mean time to failure;

– failure rate;

– failure flow parameter;

Durability indicators characterize the property of a technical object to remain operational until the limit state occurs with the established system of maintenance and repairs.

Durability indicators include:

– gamma percentage resource;

– average service life;

– average service life between medium (major) repairs.

The concept of “resource” is used when characterizing the durability during the operation of the product, and “service life” when characterizing the durability in terms of calendar time.

Maintainability indicators characterize the property of a technical object, which consists in adaptability to the prevention and detection of the causes of damage and their elimination through repairs and maintenance.

Maintainability indicators include, for example:

– average operational duration of planned (unscheduled) maintenance;

– average operational complexity of maintenance.

Note: The adaptability of products and materials to the restoration of their properties after storage and transportation is characterized by indicators of resilience.

The indicators of the recoverability of products (materials) include, for example:

– average recovery time to a given value of the quality index;

– recovery factor – the ratio of the value of the quality indicator to the specified or initial value of this indicator.

The persistence indicators characterize the property of a technical object to maintain a serviceable and operable state during and after storage and (or) transportation, or the property of a product (material) to maintain a consumable state during storage and (or) transportation.

Persistence indicators include:

– gamma-percentage shelf life;

– average shelf life.

The shelf life of a product (material) is the calendar duration of storage and (or) transportation of a product (material) under specified conditions, during and after which the values of the specified indicators are stored within the established limits.

The gamma-percentage shelf life of a product (material) is the shelf life that a product (material) will achieve with a given percentage probability.

The average shelf life of a product (material) is the mathematical expectation of the shelf life of a product (material).

Preservability indicators are evaluated by statistical methods based on test results.

Comprehensive indicators of the reliability of technical objects are the coefficient of readiness, the coefficient of technical utilization, the coefficient of operational readiness, the average total labor intensity of maintenance, the total labor intensity of repairs, etc.

In many cases, a quantitative characteristic of the reliability of the entire set of objects of this type is the mathematical expectation of a random variable

(1.1)

The form of the function X(t) is completely determined by the properties that characterize the reliability of the product.

Functional takes into account the principle that guides the consumer of the product when assessing the consequences of failures.

The reliability indicator of the product, determined by the formula (1.1), reflects the corresponding properties of the product (reliability, durability, maintainability and storability). These properties determine the nature of the function X(t), as well as the principle of assessing the consequences of failures, which is carried out by the appropriate choice of the functional .

The methodology for choosing reliability standards is based on the requirement to ensure the maximum reduced value of the reliability standardization coefficient.

In the general case, the object reliability rating coefficient depends on the cost of the object, on reliability indicators and economic indicators of operation. The reliability normalization coefficient can be represented as a function:

(1.2)

where – the cost of the product; – average losses from failure; – total costs for planned and preventive work for the service life; – specific costs for ensuring the operation of the device; – the costs necessary to ensure the completion of the task; – specific damage caused by forced downtime of the facility; – specific effect from the use of the object; – the effect of the device performing the specified functions; – indicators of reliability.

The proposed procedure for choosing the reliability standards of objects takes into account the purpose and method of their operation, the impact of failures on the total cost, as well as the current level of technology development, which determines the real capabilities of manufacturers in the expanded production.

Ergonomic indicators

Ergonomics (from the Greek ergon – work and nomos – law) studies a person and his activity in the conditions of modern production in order to optimize tools, conditions and the labor process.

Ergonomic indicators characterize the “man-product” system (in particular, “man-machine”) and take into account a complex of hygienic, anthropometric, physiological and psychological properties of a person, manifested in production and household processes.

The group of ergonomic indicators of product quality includes the following subgroups of indicators:

a) hygienic – indicators used in determining the compliance of the product with the hygienic conditions of life and human performance when interacting with the product;

b) anthropometric – indicators used in determining the compliance of the product with the size, shape and weight of the body of a person participating in the maintenance of this product;

c) physiological and psycho -physiological – indicators used in determining the compliance of the product with the physiological properties of a person and the peculiarities of the functioning of his sense organs (speed and power capabilities of a person, as well as thresholds for hearing, vision, tactile sensation, etc.);

d) psychological – indicators used in determining the compliance of the product with the psychological characteristics of a person, which is reflected in the engineering and psychological requirements, the requirements of psychology and labor for industrial products.

The nomenclature of ergonomic quality indicators applies to industrial products, as well as to their elements (equipment and workplaces; control and monitoring panels; mnemonic diagrams; instruments and signaling devices; dials and instrument indicators; plates with digitization, inscriptions and textless designations; hand and foot controls ; handles and handles of tools and controls; clothes; leather and footwear products, etc.).

The subgroup of hygienic indicators includes indicators directly related to the operation of the product:

– illumination;

– temperature;

– humidity;

– intensity of magnetic and electric fields;

– dustiness;

– radiation;

– toxicity;

– noise;

– vibrations;

– overloads (accelerations).

The subgroup of anthropometric indicators includes compliance indicators:

– design of the product to the dimensions of the human body;

– the design of the product in the form of a body and its individual parts that come into contact with the product;

– the design of the product to the distribution of the mass of a person.

The subgroup of physiological and psychophysiological indicators includes compliance indicators:

– the design of the product to the power capabilities of a person;

– design of the product to the speed capabilities of a person;

– product design (size, shape, brightness, contrast, color and spatial position of the object of observation) to the visual physiological capabilities of a person;

– the design of the product containing the source of sound information, the auditory physiological capabilities of a person;

– products (shape and location of the product and its elements) to the tactile capabilities of a person.

The subgroup of psychological indicators includes compliance indicators:

– products to the possibilities of perception and processing of information;

– products when using it are fixed and newly formed human skills (taking into account the ease and speed of their formation).

Evaluation of ergonomic indicators is carried out by comparing the values of given and basic ergonomic indicators. In most cases, the ergonomic requirements given in special reference books are taken as the basis for comparison. In this case, the assessment of ergonomic indicators is given in the form – “corresponds” or “does not correspond” to the system “man-product” to ergonomic requirements.

In cases where it is possible to determine the relationship between one of the main indicators of the purpose of the product, for example, the performance indicator and the selected ergonomic indicators, they should be evaluated by the magnitude of the change in the indicator of purpose.

Ergonomic evaluations can also be carried out by industry-specific ergonomics experts.

Example 1. When assessing the quality level of a household gas stove, a hygienic indicator is used – the concentration of carbon monoxide CO and water vapor of combustion products. According to the instructions of the Institute of Occupational Health and Occupational Diseases of the Academy of Sciences of the Russian Federation, the CO concentration indicator is estimated as follows: when the CO content in the combustion products is up to 0.03% – 0 points; 0.03% – 0.02% – 1 point; 0.02% – 0.01% – 2 points; 0.01% or less – 3 points; in the absence of CO – 4 points.

Rice. 3. The dependence of the value of the moment of rotation of the handle on its diameter

Example 2. It is necessary to evaluate the physiological indicator of tractive effort on the handles of a gas burner tap.

The assessment of the efforts required to turn the handle of the gas burner tap is carried out on the basis of the established dependence of the value of the moment of turning the handle on its diameter, shown in Fig. 3.

From Figure 3 it follows that the first, second, third and fourth zones, respectively, characterize heavy, moderate, moderate and light work. The moment created by turning the control knobs can be estimated using points corresponding to the severity of the work. So, for example, when classifying work as zone I, its severity can be assessed with a score of 1; to zone II – score 2, etc.

After evaluating the ergonomic indicators in this way, the results obtained are compared with the ergonomic requirements given in the regulatory and technical documentation or in the reference literature.

Aesthetic indicators

Aesthetic indicators characterize informational expressiveness, rationality of form, integrity of composition, perfection of production performance of products and stability of presentation.

The group of aesthetic indicators includes the following subgroups of indicators:

– information expressiveness;

– rationality of the form;

– the integrity of the composition;

– perfection of production performance and stability of the presentation.

Information expressiveness characterizes the ability of the product to reflect in the form of aesthetic ideas and cultural norms that have developed in society. It manifests itself:

– in artistic and figurative expression of socially significant information (significance);

– in the originality of the signs of the form that distinguish this product from other similar products (originality);

– in stable signs of form, characterizing the existing community, means and techniques of artistic expression, characteristic of a certain period of time (style correspondence);

– in the signs of the appearance of the product, revealing the commonality of temporarily dominant aesthetic tastes and preferences (corresponding to fashion).

The rationality of the form characterizes the compliance of the form with the objective conditions of manufacture and operation of the product, as well as the truthfulness of the expression in it of the functional and constructive essence of the product. She expresses:

– compliance of the shape of the product with its purpose, design solution, manufacturing technology features and materials used (functional-constructive conditionality);

– identification in the form of methods and features of human actions with the product (ergonomic conditionality);

The integrity of the composition characterizes the harmonious unity of the parts and the whole, the organic relationship of the elements of the form of the product and its consistency with the ensemble of other products. It determines the effectiveness of the use of professional and artistic means to create a full-fledged compositional solution and finds expression:

– in the general logic of the spatial structure of the form, its scale, proportional and rhythmic organization (organization of the volume-spatial structure);

– in the artistic comprehension of the real work of the structure and materials (tectonicity);

– in modeling, mutual transitions and connections of volumes, planes and shape outlines (plasticity);

– in the subordination of graphic and pictorial elements to a common compositional solution (ordering of graphic and pictorial elements);

– in the relationship of color combinations and the use of decorative properties of materials (color and decorativeness).

The perfection of production performance and the stability of the presentation significantly affect the features of the aesthetic perception of the shape of the product and are characterized by:

– the cleanliness of the execution of contours, roundings and joints of elements (the purity of the execution of contours and mates);

– the thoroughness of the application of coatings and surface finishes (thoroughness of coatings and finishes);

– clarity of execution of brand names and signs, accompanying documentation and information materials (clearness of execution of signs and accompanying documentation);

– preservation of form elements and surfaces from damage, erasure and change of decorative coatings (resistance to damage).

Evaluation of the aesthetic quality indicators of specific product samples is carried out by an expert commission consisting of qualified specialists with experience in the field of artistic design and participation in the work of the commission for assessing the quality level of industrial products.

The criterion for aesthetic assessment is a ranked series of products of a similar class and purpose (basic series), compiled by experts on the basis of basic samples submitted by the manufacturer and selected by experts.

When evaluating the aesthetic indicators of export products, a modern analogue of a leading foreign company is taken as the basic sample.

The process of evaluating aesthetic indicators of product quality includes the selection of basic samples and the compilation of a basic series, a comparative artistic and design analysis of the presented product and the determination of numerical values of aesthetic indicators in points using expert methods.

Example 3. It is necessary to carry out an artistic and design analysis and evaluate the aesthetic indicators of the quality of a portable electrophone (the example is conditional and is of a methodological nature).

A portable tape recorder consists of an electric player (EPU) and an acoustic speaker (AK), interlocked into a single volume. The device works from a network and from an independent power source, which allows it to be used both indoors and outdoors. Additional external acoustic equipment can be connected to the AC unit. All these design and functional features determine the nature of the shaping of the product.

Comparative art and design analysis is carried out by subgroups of aesthetic indicators.

1.4.1 . Indicators of information expressiveness of the product form

sign indicator. The artistic and design solution of the device reproduces the typical image of portable electrophones, which were popular with the consumer 5-8 years ago. Compared with the best art and design developments, the electrophone looks bulky, heavy, and its shape is unnecessarily complicated. The laconicism and compactness of the form, inherent in the best examples of modern instrumentation, are absent here. The use of new materials (expanded polystyrene, ABS plastic) does not adequately contribute to giving the electrophone the lightness and elegance characteristic of modern portable devices.

indicator of originality. In the form of an electrophone and its elements, there is no set of features that significantly distinguish it from other similar products. The layout of the controls and the main body elements is traditional. The overall compositional solution, graphics and colors reproduce the features of samples already known to the consumer.

Indicators of stylistic compliance and compliance with fashion. Modern stylistic features, reflecting the general trends in shaping in the field of instrumentation, are weakly expressed in the shape of the product. Plastic elaboration of elements (sculptural form) is not active enough. The details of the case, the control panel are heterogeneous in shape and shape, which violates the stylistic unity. There are no characteristic features of the corporate identity. The form of the product did not reflect the signs of fashion, for example, denim carrying straps were not used.

1.4.2.. Indicators of product shape rationality

Indicator of functional-constructive conditionality. The adopted layout of the device in the form of a single volume does not take into account the logic of the interaction of the main functional elements. The EPU block, designed as a removable cover, must be turned upside down when installed in the working position. The AK block, which forms the lower part of the device body, is placed on the side plane in the working position. The form accentuates elements that are secondary in terms of their functional significance, for example, grilles on the back of the EPU panel.

Indicator of ergonomic conditionality. When assembled, the electrophone is convenient for transportation and storage, which is reflected in the logic of the structure of the shape of the handle of the device, which makes it easy to carry. However, when separating the AK block from the EPU and placing them in the working position, additional efforts and time are required to reorient them in space, which negatively affects the consumer’s attitude to the shape of the product.

1.4.3. Composition Integrity Indicators

An indicator of the organization of the volume-spatial structure. The orientation of the elements of the shape of the electrophone in space in the closed and open positions violates the logic of the composition due to its obvious inconsistency. So, the cover of the electrophone in the open state turns out to be the base, and the base – the AK block – is located vertically in the working position.

indicator of tectonicity. The shape of the electrophone carries false information about the distribution of loads due to the incorrect orientation in space of its main elements.

plasticity index. The plasticity of the electrophone is complicated by numerous undercuts, bevels, etc. The shape of the secondary elements of the product is not consistent with the shape of the main ones, for example, the cord compartment cover, which has a recess, corrugations, is overly accentuated in its plasticity in the overall solution of the front panel. The shape of the electrophone is poorly drawn. The side profiles have an unordered silhouette, various angles of inclination of surfaces, numerous bevels, drops, etc.

Indicator of orderliness and expressiveness of graphic and visual elements. The graphic solution of the information elements is inexpressive, the clarity and clarity of the symbolic information of the device is not ensured, for example, the designations on the rear wall of the AK are not sufficiently visually highlighted and therefore difficult to read.

An indicator of color and decorativeness. The color solution of the electrophone does not contribute to the creation of a holistic form. The black and gray colors used divide the form into two parts.

1.4.4. Indicators of perfection of production performance and stability of presentation

An indicator of the cleanliness of the execution of joints, roundings and mating surfaces. In the form of the product, the purity and accuracy of the docking of its individual elements is ensured (there are no cracks, gaps, distortions).

A measure of the thoroughness of a surface finish. All elements of the device, made of plastic, have a smooth; uniform color surface.

An indicator of the clarity of execution of brand names, packaging indicators and accompanying documentation. Accompanying documentation for the electrophone is made at a low artistic level and is characterized by poor printing quality (poor text printing, color heterogeneity, ink misalignment, etc.).

Indicators of resistance to damage to product surfaces. The type of plastic used as a design and decorative material ensures the safety of shape elements and surfaces from chips, scuffs, fading and other types of damage during the operation of the microphone.

On the basis of the given artistic and design analysis, the experts determined the weighting coefficients of individual indicators and the value of the generalized quality indicator, given in Table. 2.

The result obtained (the value of the generalized aesthetic indicator is 2.5 points on a five-point scale) indicates that the aesthetic quality level of the assessed electrophone does not meet modern requirements.

table 2

No. p / p Single indicators Grade (on a 5-point scale) Weight coefficient m¡ m i K i
Significance 2.1 0.03 0.06
originality 2.0 0.02 0.04
Style matching 2.2 0.0 0.04
fashion fit 2.2 0.03 0.07
Functional-constructive conditionality 2.0 0.15 0.30
Ergonomic conditioning 3.5 0.15 0.53
Organization of the volume-spatial structure 2.0 0.18 0.36
Tectonicity 2.3 0.04 0.09
plasticity 2.0 0.06 0.12
Orderliness and expressiveness of graphic and visual elements 2.0 0.08 0.16
Color and decoration 2.0 0.04 0.08
Purity of execution of contours and mates 3.9 0.10 0.39
Thoroughness of coatings and finishes 4.0 0.02 0.08
Clarity of execution of brand names and accompanying documentation 2.0 0.05 0.10
Damage resistance. 3.8 0.03 0.11
∑ m i K i =2.53

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