## 2 Materials and Methods
### Limits of Action
#### 2.1.2 The Proposed \"To-Be\" Solution  
We now describe the proposed solution, focusing on the market requests, forecasts, and Takt time, as well as on the designing actions. Market Requests, Forecasts, and Takt Time  
The sales forecast for the year in which the analysis was performed (2019) indicates a request of 22,515 pieces. In the previous year (2018), the request was for 20,216 units. The data were provided by the management of the Operations Area, which interfaces directly with the company controllers. The product mix has not been calculated. Based on the provided input data, we could compute the market Takt time for the current year. The Takt time is the rate at which the market requires the exit of a finished piece from the assembly line. This is a key information in the division and balance of assembly operations, as well as in defining the number of operators necessary to meet the request. The considered input data are as follows:  
* Market request: 22,515 pieces/year. * Daily hours available: 8 h/day. * Work shifts: 1 shift/day. * Available days per year: 230 days/year. * based on internal standards). The market Takt time is computed in a single shift to maintain leeway for any peaks in requests; finally, this choice is useful for recovering the hours lost deriving from the project activity. With the given input data, a Takt time of 274 s per piece is obtained. In the following section, we describe the designed actions to eliminate the detected waste and to standardise processes. Designing Actions: Attacking Useless Movements and Useless Processes  
The attack on these Muda is defined through four reported actions, which we describe in detail below. * Action 1: The logistics workers must organise the raw material in crates. With this standardisation, operators do not have to open the packaging of raw materials, which are immediately available for assembly. Estimated time saving: 157.2 s per piece. * Action 2: The definition of standard areas for positioning finished containers and raw materials. In this way, the operator does not have to move outside his area to prepare the finished container or recover that of the raw material. Furthermore, the definition of the areas simplifies the feeding of raw material and withdrawal of the finished product, favouring the coordination of operations between departments. Estimated time saving: 26.1 s per piece. * Action 3: The introduction of a line feeding system based on customised roller conveyors, trolleys, and boxes. In this way, a unique interface is created between the logistics department and the assembly department: this enables the possibility to integrate a reordering kanban-based system that standardises the line supply signals with a consequent ease of coordination between departments. Finally, this action leads the island to operate in all respects with the lean method, abandoning the traditional work strategy. Estimated time saving of 110.1 s per piece. * Action 4: Better positioning and management of assembly instructions. This action involves the adoption of reading desks (first) and computers (later), avoiding operators constantly moving from the workplace to search for the information necessary to complete the assembly activities. Estimated time savings of 11.2 s per piece. A graph representing the impact of each action on the total of the detected Muda is reported in Figure 8.  
The actions described above lead to a reduction of the estimated cycle time from 658.8 s per piece to 354.2 s per piece, with a total saving of 304.6 s per piece. Designing Actions: Attacking Useless Warehouses and Overproduction  
Waste related to useless warehouses and overproduction mainly impacts the planning office and the logistics department. Here, the main change in the proposed solution was the elimination of pre-assemblies, which had no reason to be applied at this point in the supply chain due to the distance from the decoupling point and the Assembly-to-Order nature of the plant. As a result, the layout drastically changes, as well as the material flow.