Is there more than one crew executing this activity type simultaneously in a different workspace? How do crews move between activity types within the same workspace? How do crews move between workspaces? The fifth step is to identify the off-site flows that are required to execute each of the activity types.
The flows are color-coded as follows: labor in red, equipment in orange, workspace in blue, precedence in green, material in purple, information in pink, and external in gray. The sixth step consists of identifying if any activity type needs a flow that originates from another fragnet. This allows the method to represent interdependencies between different fragnets in the project. Step seven consists of asking field managers to identify the responsible stakeholder for each of the on-site and off-site flows.
However, sometimes the responsible stakeholder can be a supplier, a designer, or the GC. The outcome of the AFWSM is a template of the prototypical activity types and flow representation for a fragnet.
The diagram shows on-site flows joining the different activity types, off-site flows feeding the activity types, and flows interfacing with activity types belonging to other fragnets. Hence, it explicitly shows the interdependencies between activities and flows. Hence, field managers can create activity and flow schedules that can be used to plan, track, and control the project using the AFM.
This section presents the validation results of applying the proposed work structuring method on three test projects that had different scopes and planning methods. The first project was the Ichma office building located in Peru.
We tracked this project during a total of 18 weeks during its structural phase, with the lead researcher spending the first 4 weeks on site, the following 10 weeks remotely, and the final 4 weeks on site. This project was extremely sophisticated in using state of the art planning and control methods.
Field managers implemented the whole Last Planner System master schedule, phase schedule, look-ahead, and weekly. Additionally, they carried out Takt planning at the phase schedule level to design their operations: choosing how to break down the workspaces depending on the quantities and balancing the resources based on historical productivity rates. They controlled the project by using look-ahead, weekly, and daily planning.
Each activity was assigned a clearly delineated workspace. Each project engineer created a daily plan for their scope of work and tracked the daily execution against the plan, assigning daily reasons for variation to the activities. The second project was the Equilibrium residential building located in Colombia. We tracked this project for a total of four weeks during the foundations phase deep caissons. This project used traditional CPM scheduling to plan the project.
The CPM schedule was developed at very high level of detail, containing activities not exceeding one week in duration. Field managers used a CPM schedule to control the project by updating the actual start and actual finish for the activities to have a historic record of the project progress and assess schedule slippages. The third project was the Frederikskaj residential blocks located in Denmark.
We tracked this project for a total of four weeks during the interior finishing phase. All the field managers in the test projects were interested in improving the planning and control methods used in their projects. They wanted to understand whether the AFWSM could help them to better coordinate and communicate the plan among the different project stakeholders. In each of the test projects we first used the AFWSM to model the flow logic for each of the fragnets contained in their look-ahead schedule.
This was a collaborative process with field managers, who explained the construction methods and checked the representations. In the Ichma project, we modelled 5 fragnets: elevator shaft construction, structural shell construction, core beams and slabs, interior floors, and interior walls. For the Equilibrium project, we modelled 3 fragnets: caissons, in-caisson walls and columns, and foundation beams.
Finally, we modelled 3 fragnets for the Frederikskaj project: walls and in-wall MEP, floor construction, and interior finishes. This provides evidence of the generality of the AFWSM, since it was used to represent fragnets spanning three key phases of a construction project. Table 1. The average time required to model a fragnet was 15 minutes, the longest time was 20 minutes, and the shortest time was 10 minutes.
We asked field managers how much time they would be willing to spend per week to apply the AFWSM on their projects and the average reply was thirty minutes. The Ichma project represented its look-ahead schedule in a spreadsheet using a takt representation where the rows represented the activity types, the columns represented time days , and the cells contained the workspaces where the work was executed. The Equilibrium project used a CPM representation.
Finally, the Frederikskaj project used a line-of-balance representation. On average, we spent 1. As expected, the time it took to transform the schedule into an activity and flow-based representation depended on the number of activities and flows that were in the schedule.
The look-ahead schedule for the Frederikskaj project contained the biggest number of activities and took 2 hours to create. The Ichma project contained activities and took 1. Finally, the Equilibrium project contained the lowest number of activities and took 1 hour to create. It is necessary to reduce the amount of time it takes to transform the activity-based look-ahead into an activity and flow-based look-ahead for the method to be used extensively on construction projects.
Table 2. Number of activities and flows in the project 4-week lookaheads and time needed to prepare them. Project Activities in Flows in Time look-ahead plan 4 look-ahead hours weeks plan Ichma Takt 1, 1. Additionally, they highlighted how the AFWSM allowed them to communicate the plan visually between stakeholders, especially regarding the movement of labor flows between activities and workspace handoffs, leading to improvements in project coordination and plan understanding.
The AFWSM allows field managers to transform existing activity-based schedules into an activity and flow-based representation that can be used to plan and control the project using the AFM. Future research is needed to evaluate the impact of the use of the AFWSM on project performance both by collecting qualitative evaluations from users and measuring quantitative impacts through case studies. An important next step in this research is improving the time it takes to extend existing schedules into an activity and flow representation.
A potential research avenue is to automate the matching process between the activity types in the activity type and flow structuring template and the activities in the look-ahead schedule using machine learning algorithms. White paper 5. Ballard, G. White paper Bertelsen, S. Pasquire and P. Tzortzopoulos, eds.
Sacks and S. Bertelsen, eds. Darwiche, A. Dong, N. Fischer, M. EG-ICE Lecture Notes in Computer Science, vol Smith and B. Domer, eds. Frandson, A. Formoso and P. Construction Research Congress, B. Ashur and J. Irizarry, eds. Hamzeh, F. Kenley, R. Location-based management for construction: planning, scheduling and control. Koskela, L. Sacks, R. Tommelein, I. Group for Lean Construction, K.
Walsh, R. Sacks, and I. From the HRD perspective, training is one of the most important aspects to enhance people and organization development, because it powers technological and organizational change, contributes to the effectiveness of approaches that enhance quality and flexibility, and has a positive correlation with productivity improvement Guerrero and Sire, When this link does not exist soft-hard management issues it creates a vacuum in the system when we want to apply concepts, principles and tools of lean construction in the field 3 Personnel administration can be characterized by work fulfilling the law, centered in cost reduction instead of improving employee productivity, treating people as any other factor of production and generating ad-hoc solutions when some special requirement related to HRM is presented.
This gap becomes evident when you see the barriers that appear when you implement the system e. Those lead to loss of latent performance4 and could be classified as an eighth waste5.
Another way to see it is through the conceptualization of Picchi and Granja about the lean implementation scenarios Table 1 , where whatever the state of the LCP in the organization is, there is always a chance to achieve the third scenario and integrate principles, concepts and tools both in the project as in the enterprise as a whole.
The aim of this methodology was to provide a holistic view of professional roles in construction companies. In construction industry the role of the PMs as central role for project success has taken more importance in the academic side, so several studies have been carried out to find the necessary competences to perform this role in a better way. Lean construction has already approached this topic in recent years, mainly trying to find or conceptualize some characteristics of a lean leadership.
Among the most important findings from this approach are: 4 The authors call latent performancea performance that is potentially reached but due to the failures in the process or in a system as a whole whichever they were is not reached. A condition, nevertheless, is that this failures must be manageable with improvements made by people. All these approaches highlight the fact that as higher the hierarchic position of a person is, more important social skills and communication are.
Most of the investigations have been centered in studies of leadership and in defining the necessary skills to work as PM, defining skills as a series of different characteristics, behaviors and traits necessary for effective job performance.
Most of the research carried out in the construction industry indicates that the PM profile must address quite different competences, from technical and management capacity validated mainly by the experience to soft competencies. These include decision making, communication, leadership, motivation, time management, change management and negotiation.
Dainty et al, ; Odusami, Lean leadership has been approached on one hand by nine lean leadership behaviors coming from the Toyota Production System. In this system leaders are not necessarily top and senior managers, but people who are trusted and respected and able to inspire others to follow them Orr, On the other hand lean leadership was approached by the linguistic action concept where conversations are the core of the organization work and works via making and keeping commitments.
In this type of leadership, the master skill is listening Howell et al, According with the aims of this study, a very close related research was carried out in Brazil by Lantelme This study was tried to identify the development of management competencies trough experiential learning, qualifying managerial positions to introduce management innovations lean construction in the construction industry.
The result of this research was a model of management action and competence where four knowledge domains were identified: 1 technical-instrumental knowledge, 2 systemic conceptualization, 3 self-knowledge and self-domain, and 4 social-transformation interaction.
These four knowledge domains build two competences: technical competence 1 and 2 and social competence 3 and 4 Lantelme, Later on, a questionnaire that merged these skills with others provided by specialized literature Odusami, was developed. This questionnaire was applied as a part of semi-structured interviews where 16 PMs evaluated the importance of each skill for they job and which of these skills were the most difficult to apply by themselves.
According to these tasks, an evaluation form was developed in which the PM had to assign a time percentage dedicated to each task during the week. In this stage 16 people were involved. In a second stage, a time management workshop for PMs was done in which problems related to time management were discussed in detail. The results of the first study were similar to those that other investigators obtained where social skills are considered more important than technical ones.
The most difficult to apply were time management and delegation. The study was centered in on-site professional roles due to their importance for project outcomes.
The PM role was studied deeper because it is the most complete and complex role in site-organizations, so starting from there it is possible to reduce and extract some characteristics and requirements to fulfill the other site-organization roles. Extracting the main contributions and similarities of each approach, and taking the premise of the holistic development of people as a key element, five areas of competence and knowledge were identified Figure 1a. The ways in which each one must be built and developed sorted in concentric circles define the LCPP Figure 1b.
Figure 1 shows the way LCPP was built. From the five competence-knowledge areas CKA the LCPP was defined, considering first mental models that drive acting enterprise vision and lean vision and then sorting the competences needed in their complexity order looking for a holistic development of the professionals at work. In the following paragraphs it is explained why this order of CKA was selected. Enterprise vision EV : This is the first element of the LCPP because to reach effectiveness the whole enterprise and people who built it need to share common values and goals.
If people and organization do not share common values and goals people do not feel comfortable in their work and the organization can not extract the best of their capacity. Enterprise vision must drive people acting to reach enterprise goals. Lean vision LV : The lean philosophy is a new way to think and work, so it is necessary to change the typical way of acting to apply the new philosophy in the right way.
Technical capacity TC : This is the base of the professional knowledge. It contains concepts theories, rules, methods, tools and technologies mobilized to carry out the work in general terms and solve problems from the professional activity.
Management capacity MC : Is similar to technical capacity, but involves relationships in a broader context. Here it is necessary to move resources, to generate communication channels, to have a systemic view of the process and to connect the individual work with the organization work how my work is a part of a bigger picture and how it can contribute.
It is necessary to know resources, processes and people, and how they must be connected to obtain best results. Social competence SC : Social competence is cited like the difference between competent managers and leaders. It allows to develop management capacity in a better way and to make difference in performance due to the fact that organizations are social systems. It implies moving people in the desired direction, motivate them and extract the best of their own capacity. It allows developing the informal organization in the right way, which means the conversations and social networks that organization produces.
Figure 1. The LCPP was developed to state a holistic model of competences for people who work implementing lean construction. To explain how it works, the five CKA could be separate in two groups according to their main purpose. The first group EV and LV wants to state or change mental models and behaviors related to the way in which personal and organization work it is conceived by people, so it is desired that people who work under lean construction perspective think and act according the new paradigms that this new discipline compel, in agreement with organization vision and goals.
The second group TC, MC and SC wants to state what capacities or competences people need to perform their job in an effective way, considering current requirements and best practices that construction work involve. Figure 2 exposes a summary of the operation of LCPP. Figure 2. Operation of LCPP. In the case of Chilean contractor organizations, the major problem in their implementations has been related with human, cultural and organizational issues, but to the social character of the construction work probably the same problem has appeared or could appear in other countries.
Considering the literature review and the implementation problems exposed in this paper, the link between hard and soft issues in lean construction still remains weak. So that, we must evolve the understanding of lean construction as a new management philosophy and develop new ways to merge hard and soft issues as an integrated knowledge framework that facilitate the application of lean construction in contractor organizations.
Besides, it is necessary to view the company as a whole system where projects are branches or subsystems, and where integrated developments can lead the organization to become a lean organization third scenario — Table 1. This kind of application of lean construction is a major challenge but it has major potential benefits too.
This work provides guidance and recommendations to strengthen the link between soft and hard issues, approaching an essential lean philosophy element: qualification and learning for continuous improvement.
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