Atualizado: Out 15

Historicamente, os grandes desafios da área da construção civil são desvios de custo e de prazo que decorrem, principalmente da quebra de sequenciamento das atividades, programações ineficientes, e elevadas taxas de desperdício de tempo operacional, materiais e eficiência operacional.


Desta maneira, a implementação de ferramentas que permitem controle e gestão das atividades em ciclos rápidos e colaborativos são alternativas que trazem expressivos resultados para a construção civil. Rotinas definidas pelo Last Planner System (LPS), do Lean Construction e metodologias ágeis (Scrum) se ajustam muito bem na gestão dos canteiros de obra.


Lean-LPS e Agile-Scrum na indústria da construção


Na década de 1990, o Last Planner System (LPS) surgiu sob respaldo do Lean Construction como uma alternativa aos sistemas tradicionais de planejamento e controle de produção (Ballard, 2000). O LPS é um sistema abrangente e integrado para planejamento e controle de produção e é a metodologia de planejamento que vem demonstrado expressivo resultados no planejamento e controle de obras.


No último benchmark do processo LPS, Ballard e Tommelein (2016) propuseram analisar o Scrum para explorar quais elementos deste framework Ágil podem ser usados ​​para melhorar o LPS. No domínio Agile, o framework mais comumente usado é o Scrum. Scrum foi amplamente implementado no desenvolvimento de software e hardware, mas ainda não foi totalmente explorado na indústria da construção.


Scrum na Industria da Construção

No que diz respeito a metodologia Ágil, o Scrum é um framework ágil usado para gerenciar projetos complexos com grande imprevisibilidade devido à incertezas nos requisitos e tecnologia. Scrum foi desenvolvido usando uma abordagem iterativa e incremental para otimizar a previsibilidade e gerenciar os riscos do projeto (Schwaber e Beedle, 2001). No Scrum, a gestão de um projeto é dividida em Sprints, que são ciclos curtos iterativos que podem variar de 1 a 4 semanas, e consiste nos times do Scrum associados a papéis (Dono do Produto, Scrum Master e equipe de Scrum); a eventos (Planejamento do Produto, Planejamento da Sprint, Reunião diária, Revisão da Sprint e Retrospectiva da Sprint); e a artefatos (Backlog de Produto, Backlog de Sprint e Incremento). O Scrum garante transparência na comunicação entre as equipes, cria um ambiente de responsabilidade coletiva, desenvolvimento de pessoas pelo aprendizado contínuo (Schwaber e Sutherland, 2017).


Poudel et. al. (2020) comparam o LPS e Scrum em 8 dimensões diferentes através de: 1) origens, 2) propósito principal, 3) sistema geral / processo de estrutura, 4) ferramentas ou artefatos mantidos pela equipe, 5) composição da equipe e funções principais, 6) eventos regulares ou reuniões de equipe, 7) métricas / Dashboard e 8) abordagem ao aprendizado. Um resumo da comparação é fornecido na tabela a seguir:

Fonte: Traduzido e adaptado de Poudel, Roshan & García de Soto, Borja & Martinez, Eder. (2020)


Incremento do Last Planner System com Scrum


Em geral, LPS e Scrum compartilham vários princípios relacionados à forma como as equipes colaboram para organizar o trabalho e aumentar o valor entregue ao cliente. Esta combinação possibilita o equilíbrio entre flexibilidade e previsibilidade, mitigando riscos e incrementando a inovação. Poudel et al. (2020) identificaram quatro elementos principais do Scrum que podem ser alavancados para melhorar o benchmark LPS, são eles:


1) Ferramentas ou artefatos mantidos pela equipe: explorar o uso do conceito de incremento do Scrum no design de projeto. Isso pode contribuir para lidar com o aumento da incerteza, velocidade e complexidade inerente ao processo de design iterativo.


2) Composição da equipe e funções principais: melhorar a descrição da função e adicionar Scrum Master: Ter um equivalente a um Scrum Master como “guardião de regras” designado no LPS pode contribuir para lidar com alguns desafios do LPS e responsabilidades do planejamento.


3) Eventos regulares ou reuniões de equipe: explorar o trabalho com equipes descentralizadas e Scaled Agile. Isso pode ajudar a encontrar maneiras de incorporar equipes remotas ou externas ao LPS.


4) Métricas / Dashboards: explorar o uso dos pontos da história do Scrum nas métricas LPS existentes. Isso pode complementar as métricas LPS atuais em termos de consistência e correlação com a equipe geral e desempenho do projeto


Concluindo, o Scrum pode ser aplicado em todos os tipos de projetos no indústria da AEC, através do fracionamento do escopo de planejamento em sprints de 1 a 4 semanas com definição de entregáveis e tarefas prioritárias. Por meio das reuniões diárias é possível não só entender o impacto que o trabalho de cada um dos colaboradores têm sobre o projeto, mas também identificar e corrigir de forma mais ágil possíveis desvios de rota. As metodologias ágeis oferecem benefícios reais para as organizações que prosperam na mudança e que promovem uma cultura onde os trabalhadores podem contribuir para o aprendizado organizacional.


Referências:


Ballard G (2000). The Last Planner System of Production Control. Dissertation for the Doctoral Degree. Birmingham: University of Birmingham


Ballard G, Tommelein I D (2016). Current process benchmark for the last planner system. Lean Construction Journal, 89: 57–89


Demir S. T., Theis P (2016). Agile design management—The application of Scrum in the design phase of construction projects. In: Proceedings of the 24th Annual Conference of the International Group for Lean Construction. Boston, MA, 13–22


Kalsaas B T, Bonnier K E, Ose A O (2016). Towards a model for planning and controlling ETO design projects. In: Proceedings of the 24th Annual Conference of the International Group for Lean Construction (IGLC). Boston, MA, 33–42


Lia K A, Ringerike H, Kalsaas B T (2014). Increase predictability in complex engineering and fabrication projects. In: Proceedings of the 22nd Annual Conference of the International Group for Lean Construction (IGLC). Oslo, 437–449


Poudel, Roshan & García de Soto, Borja & Martinez, Eder. (2020). Last Planner System and Scrum: Comparative analysis and suggestions for adjustments. Frontiers of Engineering Management. DOI: 10.1007/s42524-020-0117-1.


Schwaber K, Beedle M (2001). Agile Software Development with Scrum. Upper Saddle River, NJ: Prentice Hall


Schwaber, K., Sutherland, J. (2017) Guia do Scrum, Um guia definitivo para o Scrum: As regras do jogo.


Streule T., Miserini N, Bartlomé O., Klippel M., García de Soto B. (2016). Implementation of scrum in the construction industry. Procedia Engineering, 164: 269–276





Recent research in Brazil identified that informal packages are executed frequently on construction sites, the exploratory studies estimate that about 30% to 35% of the tasks realized during the week were not planned and this percentage may have been higher if the Last Planner System was not implemented [1,2,3]. In this point, failure in the application of make ready process could be considered the main reason for the emergence of informal packages during the week.


An informal package is defined as a package that has not been planned at the weekly meeting but which ends up being executed during that week. Although these packages are usually neglected since it happens informally during the week and is not highlighted during the short-term and medium-term meeting, they can be detrimental to production, since their constraints are not usually removed systematically. It means that informal packages can increase Health & Safety concerns/risks, add additional activities that do not add value, change the sequence of construction tasks, increase the amount of unfinished works or reduce the quality. Others factors can explain the occurrence of informal packages, for example: (a) quality control is not integrated with production control; (b) construction is a type of site production where workers, materials and equipment move from one place to another in a large work area; (b) subcontractors normally put their interests ahead of the goals of the project because of traditional contracts that favor productivity rather than the termination of services, for example, contracts that pay per square meter executed.

The focus of this post is on highlight the root causes of informal work-packages and suggests how the Last Planner System can control it, since there are indicators that can be integrated into the routine of short-term and medium-term meeting to monitor the existence of these packages. This post presents an exploratory study carried out in a residential project in 2012. The point below presents two indicators that were developed to measure the incidence of informal packages. They can be integrated into the Last Planner System.


1. Percentage of informal work-packages


This is the number of informal work packages realized during the week divided by the total number of work-packages (formal and informal) executed. It t is expressed as a percentage. Behind all informal work packages, there is hidden information. For example, an informal work package could be a worker executing rework. To this point, the informal work packages would be classified as three categories:


  • Rework - tasks related to the correction of previously executed work;

  • Unfinished work - include tasks that were necessary due to the fact that a work-package had not been completed in the previous week;

  • New packages - consist of new work packages that had not been planned for that week.

2. Percentage of worker-hours spent in informal work packages


This indicator is based on a rough estimate of worker-hours spent on informal work packages divided by the total number of worker-hours spent during the week. Through this indicator, the management team can monitor the intensity of the work spent on the informal work package. As well as the previous indicator, the informal work packages could be analyzed as the three categories presented above: rework; unfinished work; and new packages.


The Exploratory Case Study


The study was carried out in a small building company that had a production planning & control system based on the Last Planner System, but not very effectively. The project of the study was a horizontal condominium, with 238 semi-detached houses, divided into 31 blocks, with 6,8,10,12, or 14 units, 47,05 m² or 56,8 m² per housing unit.


In the preliminary phase of the study, a diagnostic was taken to identify how the Last Planner System was implemented in the project. It was identified that the make ready process had implementation failures, since it did not happen systematically and when happened, just materials and workers constraints were analysed. The short-term planning had problems related implementation failures, since the weekly meeting did not encompass team leaders. Other problem identified during the diagnostic phase was the failure on integrating quality and production control. Since the check if the task was completed during the week did not consider the quality criteria, just if the goals of square meter was achieved. It was shown that when the quality control was realized, tasks that were considered completed weeks ago needed to be reworked during the week as an informal work package.


The purpose of the next phase of the study was to analyze the level of informal packages in the gypsum plastering process. Figure 1 shows that the number of informal packages in relation to the total number (formal+informal) of work packages is highly variable. In addition, it is possible to identify the incidences of informal packages such as rework, unfinished work and new packages during the week. This suggests a dispersion of the teams on site, since the non-removal of constraints generated disruptions in the gypsum plastering service of a house, causing the teams to disperse in search of another unit that can be worked. Furthermore, the effect of rework and unfinished work packages was very similar, since they required a worker to move back to a previous workplace, and make fairly small packages, sometimes taking more than one visit. It is happen due to this packages frequently were not considered in the make ready process.

Figure 1- Percentage of informal packages in gypsum plastering process


When evaluating the amount of working hours spent on different types of work packages, it was found that 71% of the worker-hours were spent on formal pre-planned work packages, while 19% were spent on rework activities and the final 10% were distributed between new work packages and unfinished works (Figure 2).

Figure 2- Distribution of worker according work packages


Conclusion


The quality of the antecedent service is one kind of constraints that the make ready process identify to remove before a task start. But, if there is failure to integrate the quality control with the production control or failure to implementing the Last Planner System in its entirety, informal work packages will arise during the week, as identified in exploratory study. In this point, the packages categorized into new were a result of the failure to implement make-ready process, since when a work team start the service without all constraints removed, they usually move to another work area with service front released. On the other hand, the packages categorized as unfinished work and rework were due to quality control, for example, when the task was considered complete without a quality check, the make ready process will not be effective, since the constraint “quality of the antecedent service” will not be removed. So, the make-ready process of the Last Planner System and rigorous quality control can help control the amount of informal work packages and rework. In conclusion, this study showed the importance of implementing the Last Planner System in its entirety and not to cherry-pick a few principles and practices of it, another important point is that monitoring the execution of informal packages during the week is possible to identify which principles or practices the management team should improve.

References


[1] Fireman, M. C. T., Formoso, C. T., and Isatto, E. L. (2013). “Integrating production and quality control: monitoring making-do and informal work packages.” 21th Annual Conference of the International Group for Lean Construction, (March 2016), 515–525.


[2] Ibarra, J.V., Formoso, C.T., Lima, C., Mourão, A., Saggin, A (2016). “Model for integrated production and quality control: implementation and testing using commercial software applications” In: Proc. 24th Ann. Conf. of the Int’l. Group for Lean Construction, Boston, MA, USA, pp. 73–82. Available at: www.iglc.net.


[3] Leão, C. F., Formoso, C. T., and Isatto, E. L. (2014). “Integrating Production and Quality Control with the Support of Information Technology.” 22h Annual Conference of the International Group for Lean Construction, 847–858.



Brazil’s public and private infrastructure sector is investing in processes improvement and kaizen implementation. Included in this investment is a study of the of ratio of value added vs. non-value added activities on site. The main goal of this initial diagnostic step is to understand the processes involved to provide a basis for future improvements. The study presented in this blog post involves five infrastructure projects between 2013 and 2014 and demonstrates the use of production analysis tools that allow us to understand the level of waste present in the current state of the work. In the study we have considered the Transformation and Flows perspective of production where activities are categorized as value added activities, necessary non-value activities and unnecessary non-value added activities 1,2.

The study was conducted in partnership with Steinbock Consulting, a consultancy company specialized in implementing operational excellence methodology within heavy construction projects. The company used two techniques that can provide an initial diagnosis about value added in the shop floor activities: multi-momentum and chrono analysis.

MULTI-MOMENTUM ANALYSIS


Multi Moment Analysis (MMA) is the statistical technique for determining the proportion of time spent by workers in various defined categories of activity. Multi-momentum analysis consists in observing a shop floor by regularly taking a “photograph” of the observed activities. In each picture, we count the number of employees that were in production or developing activities. We categorize employees into three areas: 1) employees who are directly adding value, 2) employees who are performing supporting activities such as transport, displacement, quality inspection (necessary non-value activities), and 3) employees who are completely idle in the form of waiting, delays, and unnecessary work or rework (unnecessary non-value added activities).

CHRONO ANALYSIS


Chrono analysis consists of recording of a shop floor activity and subsequently quantify the time of each employee spent on each step of the activity. The amount of value added and non-value added activities are calculated based on the recorded videos.

Both observations, multi-momentum and chrono analysis, were made with periods of at least 60 minutes of activity, and in some cases, whole shifts including mobilization and demobilization were considered. In total, 16 different activities were observed. Figure 1 presents the amount of time in minutes found in the observation of each activity on those construction sites.

Figure 1: Time of analysis of each main activity on construction sites (time is presented in minutes)


Two of the five projects were conducted inside the city (intracity). Those two projects were analyzed by the same perspective and the results are presented as one. The second project is a highway, the third is a railway while the fourth is pipeline for the oil and gas industry. The last project is a residential building. In total there were around 49 hours of observations on those projects. In this period, 82% are documented with a multi-momentum analysis and 18% with a chrono analysis. Figure 2 presents the amount of analysis time that were made in each project.

Figure 2: Analysis time-share of each Project


At this point it is important to state that only activities which transform resources into a product with higher value were classified as value added activities. In this way, works with large dimensions and high volume of displacement and transportation such as railways and highways result in less value added activities. Based on the observation, we found a lot of waste resulting from poor preparation of the shop floor. Idleness and high volumes of transportation and displacement were directly followed by poor preparation of routine work.

Figure 3 represents the added value level of each projects and figure 4 shows the performance of each project as well as the performance average of all projects. The green colored area shows the amount of time that the crews were adding value. The yellow area illustrates non-value added but necessary activities that cannot be eliminated in the process. Theses activities needs to be decreased. The red area represents waste.

Figure 3: Value Added level of the five projects

Figure 4: Value Added level in each of the five projects


As you can see in figures 3 and 4, there is a high percentage non-value added activities. With an average of 57%, the non-added value activities make up the largest portion of the project. By using chrono analysis and multi-momentum analysis it is clear that even companies with high technical capabilities and management team with extensive experience in infrastructure works are unaware of the level of waste that occurs in routine operations in the construction sites. By understanding the level of waste that exists we can promote a degree of urgency for the problem and convince management to allocate resources to take corrective actions. These analyses show that there is much to improve in the infrastructure sector. Given how much wasteful activities were seen in the observations, there are many low hanging fruits that can result in immediate gains in productivity by simply eliminating non-value-added activities.


REFERENCES

1. Koskela, L. (1992). “Application of the New Production Philosophy to Construction”, Technical Report No. 72, CIFE, Stanford University, CA.


2. Howell, G.; Koskela, L.; Tech, Dr. (2000).“Reforming project management: the role of lean construction”.Proc. of the 8th Conference of the International Group for Lean Construction. Brighton, UK


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