Design-in-use applied to Brazilian agriculture: The case of citrus and sugarcane harvesting

Abstract

BACKGROUND:

Harvesting is one of the most critical phases in any crop once it determines the quality of raw material obtained and future production for the next seasons. Sugarcane crops are more uniform allowing the complete mechanization of harvesting. Citrus crops, on the other hand, present variability and require special handling to preserve quality so the harvesting process remains manual preponderantly.

OBJECTIVE:

The aim of this research was to explore how the distinct characteristics of sugarcane and citrus crops influence the design of respective instruments, promoting a discussion about design-in-use in Brazilian fields and its role to improve productivity and safety.

METHODS:

Multiple case studies were conducted at 9 sites: 3 sites of sugarcane crops and 6 sites of citrus crops. Task analysis, observations, interviews, questionnaires and video footage were undertaken at each site.

RESULTS:

The modifications made by the harvesting teams in all studied sites aimed the appropriateness of objects to local conditions and real needs, transforming them in instruments, improving reliability, safety, health and productivity.

CONCLUSIONS:

In agriculture, a sector where working conditions still need to be significantly improved especially in developing countries, design-in-use appears as a solution for the problems faced by workers in the field, as an essential mean to maintain health and productivity at work.

Keywords

Instrumentalization inventiveness ergonomics equipment design

1 Introduction

Brazil is the world’s biggest supplier of sugar, orange juice and coffee [1] and is one of the few countries capable of expanding its agricultural production, considering planted area and productivity [2].

Among the States, São Paulo remains responsible for most of Brazil’s agricultural production, reaching BRL77 billion in value of production in the country [3]. Two crops, in particular, place the territory of Sao Paulo as the greatest generator of wealth in the field, the state is the major producer of orange (71,7%) and sugarcane (52,4%), with this percentage representing the total to be harvested.

With regards to harvesting, in the last decades, we can observe the process of mechanization in the most diverse cultures in the country. This is one of the most critical phases in any crop once the quality of raw material obtained and future production for the next seasons is determined. Because of those particularities, mechanical harvesting can be a challenge depending on the specific characteristics of each crop and the technology currently available.

For some time, sugarcane crops have characteristics (such as uniformity for being a type of grass) that allowed the harvester machines to be employed in the fields worldwide with satisfactory success. Since 2007, in Brazil, those machines have been adopted in a more intense process; and according to the Agricultural Economics Institute (IEA) [4], the mechanization in São Paulo State already reached 90% of the total agricultural area.

On the other hand, despite the growing advance in technologies for mechanical citrus harvesting, such as the pickup machines and self-propelled platforms [5, 6], their use is still incipient [7 –9]. According to the authors, the difficulties can be attributed to the low economic benefit, restricted entry to certain orchards and the great variability and special handling required to preserve quality in citrus crops. Therefore, the harvesting process remains manual preponderantly in Brazilian and American citrus orchards, with the use of ladders and bags, as the main harvesting artifacts [10, 11].

Although each crop has different working conditions related to the harvesting process, ranging from a sophisticated technology to simple tools, both have the same reconceptualization characteristic of unpredicted uses of artifacts.

When artifacts are introduced, they lead to development of new techniques and uses (instrumentation) and/or adaptation and transformation of devices (instrumentalization) [12]. The genesis of the instrument occurs through the workers, who adapt the artifacts in order to reduce their overload and increase productivity.

Several examples of design-in-use have been identified by studies in the most different workplaces and situations such as control rooms [13], call centers [14], chemical plant [15] and organic agriculture [16], addressing how workers appropriate artifacts designed for use, turning them into instruments adapted to their work activity. Such studies show the complexity present in interactions established among workers and artifacts, especially when there is insufficient incorporation of work reality in the design process.

The present paper intends to demonstrate that, regardless of the type of work in each crop, design-in-use has a crucial role in agriculture. Compared to other industries, ergonomic interventions and solutions have been late coming into agriculture. Thus, farmers have been historically self reliant and, out of economic and practical necessities, have been coming up with innovative approaches to solve most of their workplace problems, improving productivity and increasing comfort [17].

This paper shows some results obtained through two doctoral research projects at the Federal University of São Carlos [18, 19]. The main objective was to explore how the distinct characteristics of sugarcane and citrus crops influence the construction of instruments, promoting a discussion about design-in-use in Brazilian fields and its role to improve productivity and safety.

2 Method

The study used a qualitative research method and multiple case studies. The qualitative approach applies a systematic set of procedures to understand behaviors, values and social contexts. It seeks to apprehend the perspective of the actors involved in the problem under study [20].

Activity analysis and instrumental approach were used in this study as the core of its rationale and its main methodological line. They contribute to reveal the work reality and to reveal the artifact appropriation in work situation, achieved through the construction of workers’ competences and the interaction between actors’ representations about work activity and its determinants [21 –23].

In this scenario, the field study in real situation allowed observing the effective activity exercise, with the verbalizations taken important role in the ergonomic action, once they improve the comprehension to the main constraints of the activity and dynamics of the interactions with the artifact.

Through understanding the work activity, it was possible to discern the reasons for all the observed modifications in the artifacts made by the workers of both crops. Likewise, it was possible to identify the different uses of the artifacts in order to adapt them to different situations.

The procedures of the research in both crops involved: open and systematic observations, activity analysis, individual and group interviews, questionnaires, photographs and video footage. For each crop, there was only one researcher entirely dedicated to the study. The specific techniques to address each crop’s characteristics are detailed below.

2.1 Citrus crops

The research in citrus crops was undertaken from June/2014 to January/2017 at six cultivation sites, located in the central of Brazil’s citrus belt in the State of São Paulo. In each harvest season two different farms were studied and compared to evaluate the artifacts in real situation of use: one farm containing tall trees (above 3 meters or 10 feet) and one containing short trees (up to 3 meters or 10 feet).

A total of 107 manual citrus pickers participated in the study: 68 men and 39 women. The age of the workers ranged from 22 to 42 years and the time of experience varied from 3 to 18 years.

Interviews were also conducted with supervisors, farm managers and security technicians, totalizing 7 participants. All of them were male, their age varied from 34 to 53 and the time of experience ranged from 2 to 23 years.

- Observations: were conducted during several peak harvest periods, throughout the different stages of the harvesting process, totalizing 132 hours of observation.

- Activity analysis: involved a deep understanding of the work, expected requirements (productivity, quality, safety), different harvesting strategies, variability of orchards and trees, the use of the artifacts.

- Interviews: individual interviews were conducted during the harvesting and the collective ones during lunch breaks and at the end of the shift (especially on hot days, when most workers accelerated the rhythm in the morning so they could finish 30–40 minutes earlier).

- Questionnaires: questionnaires were prepared, tested and then provided to all the citrus pickers. The questions involved: a) evaluation of different harvesting strategies and the use of artifacts; b) modifications made in the artifacts and their perception about desirable attributes; and c) body discomfort and harvesting strategies used by the pickers in an attempt to reduce pain. The questionnaires applied to the farm managers group were intended to detail the process of purchasing and maintaining artifacts, as well as the group’s perception of changes made to artifacts by citrus pickers. Common questions of both questionnaires involved worker’s background (general data, education, experience) and evolution of the manual harvesting process and associated artifacts.

- Video footage: was conducted during the harvesting, with time varying from 20 to 40 min for each worker participating in the study.

- Photographs: were used to register the harvesting stages and the design modifications of the bags and ladders.

Considering several models of bag and ladder existing in the manual citrus harvesting, one model of each was chosen for evaluation, due to the preference of use by the pickers. To reinforce and prioritize the needs of multiple workers, a Quality Function Deployment (QFD) technique was used to understand design interactions and identify key aspects of design parameter settings.

2.2 Sugarcane crops

The research in sugarcane crops was conducted from May/2013 to February/2015 at three sites near the city of Piracicaba in the State of São Paulo: a sugar mill (location A), a company that provides harvesting services (location B), and a sugarcane grower (location C). The machines analyzed in the study were Case 8800, John Deere 3520 and 3522.

A total of 17 workers participated in the study: 13 sugarcane harvester machine operators and 4 mechanical technicians. The age of operators ranged from 21 to 46 years and three of them were women. All women were new in the job, with only 4 months of experience whereas the other operators had from 3 to 20 years of experience.

With regards to the mechanical technicians, their age varied from 37 to 45, all male, with experience ranging from 2 to 10 years.

- Observations: were conducted inside the cabins of the harvesters and tractors and also in the field within a safe distance from the machines.

- Activity analysis: involved a deep understanding of the work, expected requirements (productivity, quality, safety), actions on controls, visualization, cooperation with the transshipment and also additional activities of cleaning and maintenance of the machines.

- Interviews: individual interviews were conducted during the operation of the machines and the collective ones whenever the team was available during the season (such as during pauses for refueling, maintenance, etc.) and also during the off-season period.

- Questionnaires: questionnaires were elaborated for the operators and mechanical technicians. Common questions of both questionnaires involved worker’s general data, education and experience. The questionnaires meant for operators aimed at detailing the evaluation of the machine operated through the Likert Scale, covering various aspects related to its operation (access to the cabin, visibility, seat, acoustic comfort, etc.). The questionnaires applied to the mechanical technicians were aimed at detailing the problems frequently found in the machines, the process of purchase and adaptation of the machines, modifications made and their perception about the evolution of the design over time.

- Video footage: was conducted during machine operation, varying between 30 and 40 min for each operator participating in the study.

- Photographs: were used to register all the design modifications of the harvesting machines made by the teams.

2.3 Data analysis

Through the previously mentioned techniques, it was possible to analyze workers’ perceptions and to deepen the understanding about harvesting processes of both crops.

For data analysis, filming and recording were transcribed and keywords previously selected were used to facilitate the interpretation and description of results. After the analysis and description, the obtained data were validated with all the teams.

The study adhered to the guidelines of the ethical review process of Federal University of São Carlos. All workers participating in the study were informed about the research goals and signed a consent form.

3 Results

The design-in-use was identified in the simplest artifacts used in manual citrus harvesting and also in the complex sugarcane harvester machine. Some modifications have been used by the workers for years while others were new at the time the studies were conducted.

3.1 Citrus crops

Manual citrus harvesting involves climbing up and down the ladder carrying weight; ladder transport and handling; carrying the loaded bag either from one tree to another or to the final storage in the big bag. These activities are carried out under different climatic, terrain and orchard conditions. It is in the interaction with these various elements that workers’ real needs arise, defining the structural changes in the main artifacts: ladder and bag.

The harvest bag model most used is composed of: (a) a transverse shoulder support strap sewn into the bag body; b) bag body in which the fruit is stored, subdivided into: b1) upper storage opening, b2) false bottom, b3) false bottom support hooks and b4) false bottom support buckles (Fig. 1). All bag elements are made of polypropylene, except the buckles and false bottom hooks, which are metal.

Fig. 1

Main components of the harvesting bag.

Structural artifact modifications of manual citrus harvesting in Brazilian orchards are mainly related to the bag components. In total, 15 modifications were identified in this artifact, compared to one in the ladder. This study highlights the changes in the shoulder strap and in the bag body, performed by 85% of the interviewed pickers.

Regarding the shoulder straps, the most frequent changes are in size and in addition of coating to their structure. During use, the strap tends to curl and to adopt the wire shape, causing skin abrasions and punctual overload. To avoid this, workers increase the strap width from 5 cm (about 2 inches) to 10 cm (about 4 inches) and add a second layer of coating to provide a stable weight bearing and better shoulder weight distribution (Fig. 2).

Fig. 2

Adjustments on the shoulder straps.

In the bag body, there are three main modifications related to: the seam resistance, upper storage opening and false bottom. The first one concerns the reinforcement of the seam between the ends of the shoulder straps and the edge of the bag, in order to avoid material rupture due to the loaded weight (Fig. 3A). The second modification aims to add structural rigidity to the upper opening, by placing a piece of rubber, which facilitates access and storage, keeping that area expanded and not resting on the bag body as before (Fig. 3B). The third modification refers to the bag suitability to the body, perceived mainly from the height of false bottom when closed. This height limit is given at knee line, with size adjustment on support buckles, in order to promote mobility and space perception on the ground or ladder (Fig. 3C).

Fig. 3

A) Seam reinforcement. B) Upper opening expansion. C) Adjustment on support buckles.

Different ladder models and components were found in the same orchard. Their characteristics differed in the shape of steps and side rails, weight and height, as well as the existence of support pins and shape. Among the evaluated models, the one considered to be more adapted to the crop variability has: a) enlarged base to improve ground stability; b) step braces to increase resilience; c) hollow structural section side rails; d) non-slip steps; e) support pins for better grounding (Fig. 4).

Fig. 4

Main components of the harvesting ladder.

According to farm managers, different existing ladder patterns are due to incentives for new suppliers and manufacturers to test prototypes, once this group recognizes the ladder as the leading cause of accidents. As a result, there is a gradual replacement of the ladder models throughout harvesting seasons, based on accident analysis and workers’ performance, with manufacturers tracking the use in the field and incorporating design features based on workers’ feedback. One example of this practice is the support pin construction, an idea developed in orchards and incorporated into the ladder design, reducing sliding on sloping and/or damp ground.

Ladders maintenance is not frequent and is performed by third parties. Replacing a ladder for a new model is more common, as the transportation and maintenance logistics involve higher costs compared to purchasing a new product. Only a few corrections are made by the farms’ own mechanics, such as small welding, once these employees are focused on the maintaining agricultural machinery.

3.2 Sugarcane crops

The Fig. 5 shows the schematic view of the sugarcane harvester machine and its parts. Sugarcane harvester machines perform the basal cutting, chop the stalks into 15 to 40 cm billets (on average) and promote the cleaning of sugarcane through gravity (by the action of fans and/or blowers). Finally, the clean billets are unloaded onto a transport unit for trans-shipment.

Fig. 5

Schematic view of the sugar cane harvester machine [21].

Considering the three sites together, more than 50 modifications in the harvester machines were found.

One of the modification categories observed in the machine design was structural modifications, which include structural improvements to the machines, with reinforcements or even substitution of parts. Some preventive reinforcements are made through a welding process, called hard facing (Fig. 6A), to increase the thickness of parts such as: crop dividers, base cutter, feeding rollers, and chopper rollers. As explained: “We put on hard facing because if we don’t, it wears out, makes holes, and you have to replace the part. With hard facing, it lasts a whole season”.

Fig. 6

A) Extra welding – hard facing in John Deere 3520. B) Structural reinforcements in John Deere 3522.

The hard facing is a practice applied to all machines immediately after the purchase and also every year during the off-season period. “The original machine does not go straight to the field; hard facing is necessary and it is allowed within the warranty time”.

Other reinforcements are made correctively according to breaks and cracks that might appear in machines’ structure (Fig. 6B) and they are mainly applied to the primary extractor, chassis and elevator. “We have a lot of problems with structure. ( ... ) We work on very complicated uneven ground with slopes with hard soil, so you have to continue making reinforcements”.

Other several design modifications were made to solve specific problems identified in the every day work. Among them are the elevator’s basket and external lights.

The harvesting of smaller sugarcane produces lighter billets that might fly out of the elevator’s basket so they put chains closing up the space between primary extractor and basket (Fig. 7A). “We put these chains so the billets hit them and stay inside the basket”.

Fig. 7

A) Chains in elevator’s basket in Case 8800. B) Additional external light in Case 8800.

As the harvesting in Brazil occurs 24 hours a day, additional external lights were placed at the back of the machine to improve visibility during the harvesting at night (Fig. 7B). The lights illuminate the primary extractor so the operators can see residue removal and cleaning. As explained by the operator: “the radiator is a bit displaced to the right and we cannot see the extraction of rubbish so we put this light”.

Besides operation itself, other relevant design modifications are related to the maintenance activities performed by the operators and mechanical technicians. They aim to prevent problems, facilitate access and reduce physical effort. Among them is the wheel of chopper rollers.

When it is necessary to replace the knives of chopper rollers, the workers need to turn the so called “wheel” manually, which is difficult due to the strength required and high temperature of the wheel. The workers welded a nut at the center of the wheel so they can couple a wrench to turn it (Fig. 8). “You can move it with bare hands because it is too hot after working with the machine and also because you have to apply a lot of force. The wrench works as a lever”.

Fig. 8

Wheel of chopper rollers with a nut in John Deere 3520.

4 Discussion

Unlike other productive sectors, work in agriculture has some aggravating factors arising from the direct interference of climatic conditions, high demand for physical effort and presence of great variability [24]. The variability increases the complexity of articulation between the problem construction and its resolution, requiring changes in the activity and constant interactions to adjust work strategies.

The obtained results show that the modifications made by the harvesting teams in all studied sites aimed the appropriateness of objects to local conditions and real needs, transforming them and improving reliability, safety, health and productivity.

In the case of manual citrus harvesting, changes in artifacts contributed to: 1) reduce physical effort and pain development, which influence the performance of activities; 2) increase productivity by improving storage, space awareness and mobility, as the workers’ attention is directed to fruit selection and safety practices; 3) reduce the occurrence of accidents, resulting not only from ground imperfections, but also from the ladder instability, aggravated in the harvest of the highest fruits. Given the repetitive mechanical exposures, prolonged physical exertion, and constant weight bearing required by activities, the modifications also promote a reduction in the development of musculoskeletal disorders [17, 25], commonly associated with agricultural work, especially those involved in manual activities [26].

In the case of sugarcane harvesting, several modifications in the machines were necessary to increase their reliability so they can bear a whole harvesting season working 24 hours a day on uneven and sloping grounds. Besides the variabilities on the ground, variabilities on sugarcane stalks were also considered in design modifications to not waste lighter billets produced in case of harvesting smaller sugarcane. Additional external lights also improved visibility during work at night. Some design modifications aimed to facilitate maintenance and to minimize physical effort of operators and mechanical technicians. This is particularly relevant considering that maintenance is major source of injuries and accidents of working with agricultural machinery [27].

As proposed by the theory of instrumental genesis, when workers appropriate an artifact, it can occur through two distinct forms: either the operator develops new techniques (schemes) stemming from those he/she already disposes of, or he/she adapts, modifies the devices to mold them to their own constructions [28].

Great part of instrumental genesis in mechanized sugarcane harvesting comprises modifications in machines’ design (instrumentalization) although adaptations in schemes of usage are relevant to achieve production in unprepared plots.

On the other hand, in manual citrus harvesting, despite the significant instrumentalization of the bag, the worker also needs to search for other resources to deal with limitations and variabilities of situations, developing several different schemes of usage associated with the modifications to achieve their goal. This occurs because there are still many constraints, which are intrinsic to the manual harvesting process such as the steady weight support of the bag (on the ground and on the ladder) promoting accumulated physical fatigue and risk of accidents. This indicates that only artifact modifications (the bag) are not enough if new schemes of usage are not developed and associated; and these schemes are related not only to the bag but also to the ladder.

As the action boundaries for ladder instrumentalization are less flexible, due to the limitations related to its design and structural complexity, workers participate indirectly in the design, specifically on prototype testing phase, when manufacturers accompany the implementation of new features. Except for this period, the modifications occur through the analysis of accident causing factors, focused on the use of the ladder, with low association with other factors such as use of the bag. This particular factor is noteworthy due to the supported load and related imbalances. Therefore, regarding the use of the ladder, there is a predominant process of instrumentation, in order to provide safety and support productivity at harvest.

In the case of sugarcane, all the modifications in the machines’ design are made by operators and mechanical technicians. This form of work organization favours design-in-use, once it allows: the association of different competences, social spaces to exchange experiences and resources provided by the organization to perform modifications [29].

As stated by Rabardel and Béguin [12], users’ inventiveness and creativity are a necessary condition for the efficiency of their activities and an intrinsic property of users’ processes of artefact appropriation and the continuation of design-in-use.

In the harvesting of citrus and sugarcane, we dare to affirm that without design-in-use there is no efficient, healthy and safe work in the fields. Workers’ constructive process in agriculture is positive, as this sector is known for the need to overcome several challenges brought by different interactions.

Increasing comfort and reliability does not always require an expensive and breakthrough change. Even minor changes in simple artifacts or complex machines can improve their suitability for real conditions, as shown in this article. According to Fathallah [17] farmers employ ergonomic “simple solutions”, some of them can be used in different agricultural situations and many are relatively inexpensive to obtain or can be self-fabricated.

However, it is important to highlight that this active constructive process should not be an excuse for manufacturers not investing in design improvements of equipment and tools. In both crops presented in this study, each new machine and harvesting bag entering the fields goes through the same mentioned changes for years, without being incorporated into the manufacturers’ design. Considering the simplicity of some modifications and also the significant participation of the two crops in the Brazilian economic scenario, the maintenance of known product weaknesses for the harvesting conditions in Brazil is questioned. Would the integration of structural modifications in the design of the artifacts entail such high costs that it would not be worth done?

According to authors [30, 31], barriers to the development of health and safety initiatives, such as artefact redesign and other workplace interventions, are related not only to the lack of resources but also to other important aspects such as lack of commitment, support and managerial availability, as well as the wrong assessment of the risks present in the workplace and difficulty in involving workers.

In artifact design, ranging from simple tools to complex machines, it is imperative to foster exchanges and interventions between those who design artifacts and those who make use of and know the real work situations. As affirmed by Strambi et al. [32], in reality, only the skilled and experienced user, i.e. the operator at the workplace, is able to provide relevant feedback on real work.

Through the effective participation of workers in the design process, as in the dialogical approach [33], it is possible to articulate different orientations and points of view.

As stressed by Bourmaud [34], instrumental genesis opens an original and relevant perspective to artifact conception: the development of instruments it is not only acknowledged and expected but above all, it is targeted and tracked by the design process.

5 Limitations

Further research is needed to analyze existing methods and techniques for participatory design and ergonomics in agricultural situations, i.e. their applicability, their contributions and their limitations. Moreover, future research is needed to develop an effective framework for workers’ participation in agriculture settings.

6 Conclusions

The introduction of new technologies, artifacts, techniques may cause work overloads, mainly when such demands are not accompanied by improvements in work conditions.

Due to the particularities of agricultural situations workers are proactive in elaborating solutions that can make their own job better.

In agricultural situations, participative design and ergonomics are essential to move design process beyond prescription of tasks, optimizing user-artifact interaction in order to obtain better coupling and work efficiency.

Although it is well-known that workers are aware of the real needs and their own perceptions are crucial to obtain a correct diagnosis that can lead to effective ergonomic interventions, participative methods are not effectively employed.

Better design of artifacts for harvesting (manual or mechanized) has a significant effect on feasibility, economic profitability and aspects of safety and health. However, for this to occur, two things are imperative: 1) dialogic spaces must be created and encouraged among different actors responsible for harvesting and 2) workers must be recognized as active contributors to artifact design.

Thus, this paper seeks to encourage designers and manufacturers to rethink their design practices, incorporating the real work perspective to produce more comfortable and safer artifacts. In addition, the data provided can be relevant for standard setters and inspection bodies to contribute to their interventions in health promotion and injury prevention in agriculture.

Conflict of interest

None to report.

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