Introduction

The Indian construction sector is forecasted as being among the fastest growing in terms of construction output due to economic growth and urbanization in the country [1]. However, the sector is still plagued by several existing and impending project delivery issues [2]. With a construction demand poised to exceed US $ 500 billion from infrastructure and real estate projects during 2012–2017, the sector needs to tackle issues such as lack of project delivery standards and inadequate use of technology across the construction supply chain [3]. Time and cost outruns [4–6]; irregularities in procurement [7]; and below par performance on development projects amongst its peers [8] are among the most pressing challenges currently weighing down the construction industry in India.

The multitude of challenges faced by Indian construction sector have been creating a restrictive environment to the effective delivery of projects and in turn responsible for the sectors constrained growth. Lack of coordination and mistrust are commonly cited reasons for the current state of the Indian construction sector. This by itself creates the need for testing of a different project delivery approach and adoption of an efficient project operating system.

Around the globe stakeholders in the construction industry are shifting towards the lean principles and practices for efficient project delivery and for addressing issues cited above. Should such a shift take place in India also? Can lean principles be adopted by the Indian construction sector to tackle some of these challenges? Is lean a panacea for the troubles that Indian construction faces? This work attempts to answer these questions by undertaking a case study approach and highlighting possible transformational forces that address mistrust and lack of coordination in the industry.

Lean, seen by many as a goal (being lean), as a continuous change process (becoming lean), as a set of tools or methods (doing lean/toolbox lean) and as a philosophy [9], has more to it than its shallower interpretations of waste elimination and waste minimizing tools. Having its roots in the Toyota Production System (TPS) [10], implementing lean in core business processes is said to change the way organizations or an entire sector operates. Having continuous improvement (kaizen) and respect for people at its foundation, lean involves adopting a ‘challenge all’ and ‘embrace change’ attitude [11]. The construction industry, on understanding the potential benefits of this approach, embraced these principles by distinguishing it as ‘lean construction’ [12].

Lean construction was chosen in this research to explore possible ways of making project delivery more efficient in India. Specifically, LPS, a popular lean construction tool [13], was selected for further exploration and implementation. This work reports on the case study research conducted to capture the benefits of LPS and implementation difficulties in the Indian context.

Overview of Lean Construction

Lean construction, a concept that is not entirely new, emerged from the successful application of lean philosophy in manufacturing with a fundamental intention of identification and elimination of waste while simultaneously accomplishing client needs by Toyota’s engineer [14]. Lean construction is defined as ‘a production management-based approach to project delivery–a new way to design and build capital facilities’ [15] with ‘A pursuit of concurrent and continuous improvements’. Koskela [16] was the first to challenge the construction industry upon finding this novel concept’s adoptability and similarity to construction and project delivery processes. The first ever documentation of the expression ‘Lean Construction’ was at the 1993 conference by the International Group of Lean Construction (IGLC). Thereafter the researchers and practitioners worldwide have diffused lean thinking into their respective construction sectors such as North America (US [17]), Europe (UK [18], Germany [19], Finland [20, 21], South America (Brazil [22], Chile [23], Ecuador [24]), Middle East [25], South and East Asia (Singapore [26], China [27]) and Australia [28].

Although the implementation of lean is possible at the project level or at the organization level, many implementers of lean focus on the construction site level. While the lean philosophy is viewed as ‘commonsensical’, implementation can be quite challenging. In countries like India additional challenges are anticipated. Low availability of core professionals, limited use of standards and project management techniques, cultural and social issues, low awareness and other mindset barriers need to be overcome when implementing in these countries. Reports of low adoption of lean principles by Indian construction companies is available in literature [29].

Like any approach, lean construction is applied to projects using a variety of tools and techniques that focuses on improving the delivery of projects throughout its lifecycle and generating value for all stakeholders. There are several widely used lean tools in construction [30, 31] such as Lean Integrated Project Delivery System (LIPDS) [32, 33], Just-in-time (JIT) [34], Waste Walk, 5S system, A3 reports, Value stream mapping [35], and LPS [13].

Among the commonly used lean tools, the LPS is seen as the most popular. Since it works in a manner that eradicates the deficiencies of the traditional Critical Path Method (CPM) [36], successful implementation has been reported widely. [37] The researchers have reported findings from 26 cases that implemented LPS. Many benefits of LPS such as improvement in project delivery, creation of a more predictable production program, reduction in project duration, better cost management, reduced stress on project management staff, and improvement in the overall production process have been reported in literature [38]. Due to this reason LPS was selected for the case study in this research.

Last Planner System

The prior investigators [13, 39] have been credited with the development of LPS. They define LPS as “a philosophy, rules, procedures, and a set of tools that shifts the focus of control from the workers to the flow of work that links them together and thus proactively managing the production process” [13]. LPS is described by several researchers as an approach that gives definition to workflow while accounting for construction uncertainties thereby improving predictability and reliability in project delivery [40]. The research on which it is based began well before “lean” became part of the management vocabulary, with initial experiments being conducted as early as 1980s [13]. In LPS, as the name suggests, the power to shape the project progress rests on the “last planner” or project staff who are at the workface, so that they can involve themselves and commit to the tasks that can be accomplished for the planned week [13]. The LPS has been tested internationally by academicians and industry experts to demonstrate consistency in project delivery processes in construction projects within the US [41], the UK [42], South America [43], the Middle East [44], Korea [45], among many others. Also large-scale complex projects have reported improved productivity and lower workflow unevenness with the application of LPS to their construction phases [33, 46].

The concept of the LPS has five main sequential stages [39, 47, 53] as shown in Fig. 1. At the topmost level, the Master-plan is used to create a broad plan which categorizes the work packages of the entire project. It brings out duration of the key activities in sequence.

Fig. 1
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LPS implementation steps

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Second stage of phase planning breaks down the master plan into major phases detailing work plan and creating trade wise goals that can be monitored as milestones. It connects the master plan to the look-ahead planning stage. At the third level 6-week look-ahead planning connects work to be undertaken on site over the short term. The focus is shifted to making resources ready for the anticipated tasks, phasing out constraints for smoother work flow thus replacing firefighting mode with a proactive approach to task completion. The researches have [47] indicated that look-ahead schedules are tools to control work flow acting as a link between master schedule and weekly work plans. Activities are not allowed to enter the look-ahead unless constraint analysis is conducted and promise for execution from respective stakeholder is sought. The duration of look-ahead plans varies from 3 to 12 depending on the complexity of project but 6 week time frame is usually used in practice.

Constraint identification is started along with the look-ahead plan to make the tasks ready for execution ensuring that the necessary materials, machinery and information are available on time (screening and pulling mechanism). The number of people involved in preparing these look-ahead plans should be as high as possible as a single person cannot identify all constraints in a construction project. New constraints might enter during these 6-weeks which should be identified and removed.

The look ahead planning trickles down to the fourth element of weekly work plan where last planners at site, who are usually the foremen or supervisors, promise to deliver work found achievable in the coming week. Tasks are entered into the weekly work plan only after resolving all the identified constraints. In case all the constraints are not removed, the work must be re-scheduled for a later date. The key terms in the weekly work plan are ‘Should’, ‘Can’ and ‘Will’. ‘Should’ indicates works to be done according to the look-ahead schedule. ‘Can’ indicates the work which can be achieved due to removal of various constrains. Upon considering all constraints the works committed by last planners are then indicated by ‘Will’ [30, 48].

The concluding step in LPS is the Feedback Statistics which uses the measurement index of PPC (or promises) calculated as ‘DID’ activities upon ‘WILL’ activities. Also a list of reasons for non-completion of activities substantiates the planning phase by registering them in a database. This helps in continuous improvement.

LPS implementation is reported to be challenging. According to past studies, if an organization is planning LPS adoption, a good place to start is by gathering data from its projects about the percentage of tasks delivered on a weekly basis. So going by the adage “if you can’t measure it you can’t manage it” collecting data and calculating PPC over a period of few weeks may convince the management to look towards LPS implementation. Ballard and Howell point to the lack of training of site staff on a frequent basis as a major challenge in LPS implementation [49].

Case Study

The purpose of this research was to demonstrate the applicability and benefits of LPS in the Indian context and to demonstrate that indirectly LPS promotes better coordination and trust among project team members. The notion that Indian construction projects and project teams are culturally different to the ones where lean principles have been successfully adopted had to be confronted. In this research an actual implementation of LPS as an action research initiative was conducted to answer some of these unanswered questions about practicality of LPS in the Indian context and benefits to the involved organizations [50]. It was decided to select an industrial construction project for this study, a large automobile factory in western India. Action research process adoption is justified, as it gives flexibility and at the same time allows learning from the change created on implementing an action within managerial practices, thus adding research value and understanding [51, 52]. The overall flow of the research activity is shown in Fig. 2. The implementation of LPS on the case study was started when the researcher stationed himself on the site as part of project planning and monitoring team. The contractor had two large-footprint industrial buildings to complete. The master schedule prepared for the project after identification of various milestones based on contract agreement at the starting of the project itself became a key resource for LPS implementation. Before implementing the LPS, the researcher calculated and analysed PPC for a period of 15 weeks.

Fig. 2
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LPS implementation plan for the case study

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In this case study project, data from the project site was gathered and percentage of tasks delivered in a week to that planned for that given week were identified. Prior to beginning LPS implementation, look-ahead plans were prepared based on the current status and activities to be executed during the next 6 weeks were broken down into sub-parts. Look ahead plan was updated at the end of every week. Whenever an activity entered the last window of look-ahead plan, it was broken down into sub-activities.

Constraint analysis was carried out for the activities that entered into the last window of look-ahead plan and solutions for the constraints were found out during the 5 weeks. The site engineers provided the planning team with the activities that they were planning to execute in next week based on the look-ahead plan. The planning team ensured the commitments using constraint analysis, prepared weekly plan and finally a check was made by site in-charge before the work was committed.

At the end of each week, the reasons for failure in activities committed was analysed using daily progress reports and by taking feedback from the site engineers. PPC was measured to monitor the performance of the two buildings and overall project as shown in Table 1.

Table 1 PPC calculations for the case study
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Results of Implementation

After the 15 week data collection (pre-LPS), LPS was implemented for a period of 8 weeks in close collaboration of the project team. The researchers remained embedded in the project team and conducted many formal and informal interactions to explain, learn and discuss issues surrounding LPS implementation. Extensive data collection took place during these 8 weeks. Using this data weekly PPC values were calculated and shared with the team members. Summary of the PPC calculations is shown in Table 2.

Table 2 Percentage of tasks completed every week
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The results of PPC before and during the implementation of LPS are shown in Fig. 3.

Fig. 3
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Variation of PPC before and during Implementation

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Reasons for failure of weekly plans were also identified at end of every week. The reasons for failure and their frequencies are shown in Fig. 4. Reasons for failure were initially categorized into 10 types and ‘hold by client’ was added as an eleventh option due to its high frequency of occurrence. Predecessor availability on time is the major reason identified for failure occurred thirteen times during the implementation period followed by hold by client and others with a frequency of nine each.

Fig. 4
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Reasons for failure and corresponding frequency of occurrences

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Plan failure reasons were categorized into execution or planning failure based on the causes. 58 activities failed to be completed during this period, out of which 38 were plan failures and 20 were execution failures. It was identified that plan failures contribute 65 % of total failures which shows that better planning increases the work flow. Similarly 62 % causes of the failures were found to be due to internal reasons such as machinery, materials, submittals etc., which can be avoided, and 38 % of the failures are due to external reasons such as weather, design changes, hold by client etc.

Of all the reasons for incompletion of work planned for the week, the most frequent constraint observed during the 8 weeks of LPS implementation was incompletion of predecessor activity, which occurred for 13 activities over the 8 weeks. However towards the last 2 weeks of observation, constraints that occurred were observed to be limited to only labour shortage, a problem owing to the unorganized nature of labour forces and material unavailability. Predecessor activity incompletions were eliminated to a large extent due to the last planners being able to keep to their commitments and to contribute in a collaborative planning process.

Conclusion

The LPS implementation brings along effective relationship which form the backbone of a stabilized project based-production system that the tool advocates. The implementation of the new tool on a construction site progresses through a learning curve which ultimately results in creating value. This study identified and tested the effectiveness of LPS, a lean construction tool in improving the PPC. The aim of this study was to examine how constraint identification and failure analysis during planning and execution stage of the project can manifest success on construction sites in India. Maintaining different durations for identification of constraints in planning and execution should also be considered as the constraints in execution will be difficult to identify much before actual execution. Providing training to employees is a key to successful use of lean construction tools. An organization involved in testing and successfully implementing lean concepts in construction project management would stand to benefit not only in terms of duration reduction but also in cost savings. From the research, it is found that predecessor availability on time is the major reason identified for failure occurred during the implementation period followed by hold by client and others. Plan failure reasons were categorized into execution and planning failure based on the causes. This clearly shows that lack of coordination between the project team members is an important challenge. The study recommends that contractors and construction managers should pay keen attention to the prevalent causes of failure during planning in order to minimise their occurrence at construction stage. Implementation of LPS on this case study has been identified as a successful tool to increase the productivity on site demonstrating proficient results by achieving an increase in PPC.