Improvement of Manufacturing Operations through a Lean Management Approach: A Case Study in the Pharmaceutical Industry

2.1 Literature review

‘Lean Production’, or rather ‘Lean Management’ is an intellectual approach consisting of a system of measures and methods which, when considered as a whole, have the potential to bring about a lean and, therefore, particularly competitive state in a company. The main fields of activity concerned are product development, the supply chain, shop floor management and, to a lesser extent, after-sales services [9]. There are multiple ways to combine the individual practices in order to represent the multi-dimensional nature of Lean Manufacturing [10], which is the reason for the considerable amount of literature on the topic.

Following its dramatic successes in manufacturing in the pharmaceutical industry, many companies have chosen to implement a Lean Management approach in order to accomplish such goals as decreasing waiting time to release products onto the market, to reduce production waste, improve communication with end users and raise quality levels, both in the course of production and in testing laboratories.

Most of the research work is aimed at supporting the implementation of Lean Management in the pharmaceutical industry: [11] states that Lean Management could transform the Pharma Industry. A more frequently covered topic is the current state of Lean Management implementation [12]. Some researchers have focused on typical contextual factors, such as plant size and company type, that have an influence on the degree of implementation of lean practices [13]. Others have identified some barriers to the success of Lean Management, as well as their potential mitigation [14]. Many others have worked on the financial returns on investments from Lean Management [15], as well as on the potential benefits of the operative parameters [16, 17, 18].

Many authors have benefited from the application of Lean Manufacturing concepts to different pharmaceutical areas, such as R&D [19, 20], clinical laboratories [21] or clinical supply chains [22]. Finally, even harmonization with legal regulations, as represented by the requirements for Good Manufacturing Practice (cGMP,) has been studied [23].

In most cases, Lean Management is analysed in combination with Six Sigma [24]. The idea for the research presented in the paper originated in the work of Goetzfried and Basu [25], who state that most of the companies are stable enough to work to achieve effectiveness goals using Lean Management. The literature is thus not lacking in references to Lean Management in the pharmaceutical industry, which can be consulted in order to increase efficiency.

3.1 Objectives

The management has decided to implement a Lean Management approach, but the main focus has been on achieving efficiency through improvement activities which are aimed at:

Within the general improvement programme, we have focused on a specific project that has been developed in two synergic ways in a pilot production flow:

Both methods have contributed to the following goals:

Concerning the latter goal, the main problem was an excessive walkthrough product, which divided production flow into different production areas.

In the following sections we present the details of the activities the company has implemented on the pilot production line. These activities are characterized by a high level of technology and innovation, but which have never been reviewed under the Lean Management principles. This allows for an appreciation of the contribution of the methodology in terms of efficiency.

3.2 Re-engineering of the production flow

The process of drug manufacture (Figure 3) can be broken down into a series of steps:

The production flow is characterized as having a buffer just after the second blending for technical reasons. Moreover, cycle times up to the second blending were really similar and completely different from the second part of the flow. This creates the impression of a two stage production flow.

In line with the Lean Management approach, the value stream map method was used in order to eliminate various kinds of waste, such as:

On the other hand, the specific goal pursued by the reengineering of the production flow was a layout design. The goal includes some sub-objectives strongly linked to the Lean Management:

With reference to the creation of a continuous production flow, pharmaceutical manufacturing has traditionally been a batch-wise process. However, several factors (reduction of cost, improved process efficiency, optimal use of equipment, flexibility in production capacity) encourage the pharmaceutical industry to investigate the opportunities offered by continuous processes [26]. Various technological advances (as mentioned above in tableting and granulation phases) have made this possible.

From an organizational point of view, the main obstacle to making the flow continuous was the presence of a bottleneck. According to Králová and Bielak [27], a production flow bottleneck can be individuated by calculating the average rate of utilization for each workplace with respect to the whole-system average of this rate. An operation with the minimal value of the rate of utilization is regarded as a bottleneck. In the case study the bottleneck was the tableting operation. The lower severity was for the packaging workplace. Both workplaces needed an expansion of capacity.

In order to remove both bottlenecks, the production machines were replaced with machines that were more advanced, from a technological point of view. This allowed for:

3.3 The pull-based production system implementation

The production flow performs a pull-based production system in order to define the inventory level. However, a specific goal for the company was to reduce WIP (see section 3.1). That is why the implementation of a hybrid Kanban-CONWIP system (Constant Work in Progress) was carried out.

The CONWIP system was introduced by Spearman, Woodruff and Hopp [28]. The basis of this system of operation is that, in order for parts to be admitted into the line, each part container should have a card attached to it. When a container is consumed at the end of the line, the card attached to it is returned to the beginning of the line, and is subsequently attached to a designated part container before being readmitted to the line. Thus, the consumed container is replenished upon completion of the designated part. CONWIP systems can achieve a lower WIP level than Kanban systems [20], because WIP is equal to the number of CONWIP cards in the system.

According to [29], there are some benefits of controlling WIP, such as:

Sometimes it is possible to combine the benefits of a hybrid Kanban-CONWIP system. This is outlined in the case study in which the specific shape of the flow suggests that it could be split into two parts. One is controlled by a pure Kanban system (the focus being on the inventory level of each workplace), while the second is controlled by a mixed Kanban-CONWIP system (the focus here is also on WIP).

In Figure 4 we reported the final result of the implementation of the pull-based production system.

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Figure 4.

The production flow after the Kanban implementation

Since a CONWIP system behaves as a push system inside a black box, each workstation will continue to process work as long as there is work in the queue in front of it. WIP will tend to accumulate in front of the bottleneck workstation. However, a queue explosion does not occur as it does in a push system, since card control limits total WIP [29].

3.6 Analysis of results

The re-engineering of the production flow through Lean Management and the implementation of both Kanban and CONWIP led to the following results after 90 days (Table 1):

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Table 1.

Results after 90 days

Goal	Target	Results
Total Pipeline Lead Time Reduction	6 days	5 days
Throughput Time reduction	3 days	2 days
WIP reduction	30%	37%
Lay-out redesign (walkthrough reduction)	300 mt	284 mt