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


Atualizado: Jun 15

Desde que foi concebido em 1994 o sistema Last Planner tem sido amplamente implementado por diversas empresas mundo a fora em busca de garantir uma maior previsibilidade em seus projetos. Ao longo dos anos algumas melhorias foram sendo incrementadas ao método original, e mais recentemente uma delas tem se tornado destaque em diversos canteiros de obra do brasil, o Check-in/out, que também é conhecido na literatura como Daily Meetings ou mesmo Huddle Meetings.


O Check-in/out pode ser considerado como o 5º elemento do sistema Last Planner (Long Term Planning, Pull Planning, Lookahead Planning, Weekly Planning) e tem função fundamental para auxiliar as empresas a evitar que pequenos desvios diários tomem proporções significativas. Parte dos estudos na área já vinham identificando que para alguns tipos de obra a implantação dos 4 elementos do Last Planner não era suficiente, pois o PPC semanal raramente alcançava 100%, o que demonstrava que condições de incerteza ainda surgiam ao longo da semana além de não garantir o atendimento ao prazo de obra.


Neste ponto, um estudo recente demonstrou que o uso do Check-in/out pode resultar em um aumento de 15% da média do PPC (Grande, 2019).


De uma forma geral, o Check-in/out é uma reunião diária em que o Coordenador de produção ou Supervisor da produção tem com os principais encarregados para alinhar as metas a serem produzidas no dia e remover obstáculos que possam vir a prejudicar as equipes a alcançarem esta meta (Figura 1). Ainda nesta reunião, os encarregados devem apontar o avanço realizado do dia anterior, o que permite a equipe de gestão da produção identificar se a meta semanal prevista no plano de curto prazo será alcançada ou não. Este fator é muito importante pois caso seja identificado, por exemplo, que na quarta-feira que existe um risco grande de uma atividade não ser concluída, a equipe de gestão pode tomar ações corretivas como trabalhar uma hora extra a mais, redistribuir recursos, trabalhar no sábado, e etc. Em outras palavras, o Check-in/out funciona como uma forma estruturada de acionar a cadeia de ajuda para auxiliar a produção na resolução de problemas que venham paralisar alguma frente de serviço.


Figura 1 – Reunião de Check-in/Out


Mas, antes de sair por aí tentando implementar em sua obra, segue algumas questões iniciais que você precisa saber:


Qual tipo de obra deve ser aplicado o Check-in/Out e para quais serviços?


A partir de nossa experiência prática criamos uma matriz que auxilia aos gestores identificar qual tipo de obra merece aplicar o Check-in Check-out e para quais serviços devem ser aplicados. Na Figura 2 é possível identificar dois eixos principais na nossa matriz, o eixo horizontal que trata da duração do projeto, e o eixo vertical que trata da complexidade do projeto.

Projetos mais complexos, onde existe muita interdependência entre frentes, incertezas referentes aos projetos, indefinições do cliente ou mesmo reformas em prédios que estão em funcionamento tende a ser obrigatório o uso do Check-in Check-out, seja esta aplicação total (para projetos com curto prazo de execução) ou parcial focada em serviços do caminho crítico (para projetos com longo prazo de duração). Por outro lado, projetos pouco complexos, onde existe uma grande repetitividade do produto tende a ter uma aplicação parcial focada em serviços críticos (para projetos com curto prazo de execução) ou não necessita a aplicação do Check-in Check-out (para projetos com longo prazo de execução).


Figura 2- Matriz Duração x Complexidade


Quanto tempo deve durar a reunião?


A reunião deve ser focada, durar no máximo 20 min, para isto, os encarregados devem ter deixado registrado antes da reunião a aderência com relação a meta diária e o principal problema que impactou para o não atendimento.


Qual indicador devo utilizar?


Um dos indicadores sugeridos é o de aderência diária, que avalia qual a aderência da produção para a meta alinhada no dia anterior. Lembrando que as metas diárias devem ter sido planejadas para serem feitas ao longo da semana no planejamento de curto prazo. Para os casos em que a meta diária definida no Check-in Check-out não foi planejada para o curto prazo, a aderência deverá ser igual a 0. Outro indicador importante é o indicador de produtividade, o qual pode auxiliar os gestores a tomar decisões para melhorar a produtividade de uma equipe.


Referencias bibliográficas


GRANDE, F. Modelo para Implementação do Gerenciamento Diário no Processo de Planejamento e Controle Operacional na Construção Civil com foco na Gestão Visual. 2019. Dissertação (Mestrado em Engenharia) – Programa de Pós-Graduação Stricto Sensu em Engenharia Civil – IMED, 2019.

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