Cultivos celulares

According to Shah and Ward (2003) lean practices are associated with high performance.

The authors further stated that the implementation of lean practices is associated with improvements in operational performance measures. The most commonly cited advantages related to the adoption of lean practices are improvements in labour productivity and quality, as well as reduction in cycle time, manufacturing costs and customer lead time (Shah and Ward, 2003). Shah and Ward (2003)’s research have investigated the impact of the practices associated with several lean bundles/categories (TQM, HRM and TPM) but no mention has been made of the impact of lean practices on any one of cost, sales or profits.

2.6.1.1 Impact of Lean on Costs

Mackelprang and Nair (2010) believe that cost performance is positively related with set up time reduction, pull system, uniform workload, lot size reduction and preventive maintenance. In other words these practices identified by Mackelprang and Nair (2010) help in the reduction of manufacturing costs. Nakamura et al. (1998) also agrees that preventive maintenance helps improve performance costs because it helps minimize the average percentage downtime of machinery due to failure as it helps to minimize losses from wages that must be paid despite the stoppage of work due to machine failure.

Kumar et al. (2013) states that material handling contributes to the total manufacturing costs by between 15% and 75%. The authors argue that this may be due the poor layout of facilities. This implies that a poor cellular layout of the manufacturing facility may lead to an increase in total manufacturing costs. This then entails that a suitably reengineered production process involving the appropriate physical layout of facilities and equipment could in fact mitigate the negative impact on manufacturing costs ascribed to material handling and related practices. Other lean practices as identified herein that could be closely matched with material handling are focused factory and planning and scheduling, these help reduce costs.

On planning and scheduling, Eyong (2009) states that when providing customer satisfaction can be directly translated into reduced cost.

Liebesman (2009) believes that the elimination of variability which tallies with uniform workload helps reduce costs. Group technology has also been identified by Vázquez-Bustelo and Avella (2006) as a practice that provides key advantages for production centers while lowering costs. Through employee involvement (multifunction employees, self-directed work teams and quality circles), resources required to monitor employee compliance (e.g., supervision and work rules) can be minimized, hence reducing costs (Hibadullah et al., 2013).

Amin and Karim (2013) believes that implementation of the lean strategies just in time (JIT) and total productive maintenance(TPM) does not automatically increase profit of a firm as the benefits derived from their adoption may be offset by their many direct and indirect costs.

Because, the adoption of both JIT and TPM requires extensive training of employees on pull concepts; identification of key performance measures; new layout based on U-shaped cells;

standardisation of operations; a maintenance procedure for each machine; housekeeping, visual control and multi-skill training (Amin and Karim, 2013). The authors also believe that choosing to implement both JIT and TPM together without due consideration of the undesirable impact they may have on each other may lead to increased implementation cost. The benefits of Kanban according to Edward (2007) are realised in the longer term as a result of their high implementation costs.

2.6.1.2 Impact of Lean on Lead time

Sharma et al. (2015) performed multiple regression analysis to examine the impact of several lean manufacturing practices on lead time (The manufacturing practices being the

reduction in set up time leads to a significant reduction in lead time, hence improving the lead time performance. Sharma et al. (2015) expressed surprise at the negative coefficient observed for total productive maintenance (preventive maintenance) as it was contrary to popular belief with respect to lead time reduction. This result is surprising given the fact that regular maintenance practices prevent machines from pre-emptive break downs thus reducing throughput time. The benefits of preventive maintenance in improving manufacturing lead time could have been achieved had the responding firms implemented preventive in its entirety. In fact, many firms that participated in the study fell short on this account Sharma et al. (2015). Other practices which were observed to have improved include quality circles and total quality control.

Reducing lead time for a fixed service level requires a reduction in average cycle time (Singh et al., 2013). Other practices believed by Singh et al. (2013) to reduce lead times include set up time reduction, bottle neck removal (also identified by de Treville et al., (2004)) - as the symptoms of bottlenecks/constraints include congestion slowdowns, queue formation and shipping delays. The authors observed that when bottlenecks were removed or reduced the average velocity of the production traffic increased. Time based competition, lot sizing (production in small/large batches), continuous flow production are other practices identified by de Treville et al. (2004) to contribute positively in the reduction of lead times.

Aitken et al. (2002) states that several designers co-operate and concurrently work on the same project hence increasing the intellectual capacity of the division and compressing lead times. Hence by extension, the lean practice quality circles could be of help in reducing lead times.

Focused factory and continuous flow production are also practices believed to reduce lead times as simplicity, repetition, experience and homogeneity of tasks are qualities which make that possible (Singh et al., 2013).

Continuous improvement helps expose wasted time within the organisation, and once it is exposed, it becomes a lot easier for the employees to identify and subsequently eliminate it.

Hence continuous improvement helps reduce lead time through its capability to expose and eliminate wasted time (Zhang, 2008).

2.6.1.3 Impact of Lean on Waste

This could be viewed from the point of that lean and green have certain commonalities as discussed in previous sections. Sroufe, (2003) cited in (Yang et al., 2011) contend that firms

environmental management and that environmental management encompasses activities from product development to final delivery and disposal of products.

Also, the waste reduction techniques of both paradigms are often similar, with a focus on business and production process practices (Bergmiller and McCright, 2009b in Dues et al., 2012). Waste reduction through a change in business practices is achieved by an adaptation of a corporate company culture (Mollenkopf et al., 2010 in Dues et al., 2012). This means changing the company’s vision and integrating Lean and Green practices into support functions, such as administration and building maintenance. Both Lean and Green paradigm look into how to integrate product and process redesign in order to prolong product use, or enabling easy recycling of products as well as making processes more efficient, i.e. less wasteful (Sarkis, 2003 and Bergmiller and McCright, 2009b in Dues et al., 2012).

Modi B and Thakkar (2014) contend that effective preventive maintenance is a lean tool which eliminates equipment breakdowns, defects, scrap and rework, mini stoppages and reduced speed. It can therefore be said that since it eliminates defects and scrap among other things, it will also reduce waste generated.

Generally, lean orientation may help firms to adopt environmental management practices which aim at reducing pollutants and environmental wastes (Yang et al., 2010 in (Yang et al., 2011).