How to calculate production capacity of injection molding factory

Time:2022-06-14 09:18:58 / Popularity: / Source:

Production capacity (capacity) is an important issue for all businesses and at all levels of business. Production capacity refers to maximum that an operation unit can handle at full capacity.
A unit of work here can be a factory, department, machine, or individual worker. Keep following in mind when calculating productivity:
injection molding factory 

01 Determining unit of calculation of production capacity

Due to wide variety of enterprises, products and production processes of different enterprises are very different. Before calculating production capacity, unit of measurement of production capacity of enterprise must be determined.

(1) Input and output

Production capacity is closely related to input and output, different enterprises can choose input or output as measurement unit of production capacity according to their own nature and other circumstances.
When an enterprise takes output as unit of measurement, it needs to consider how many types of products enterprise produces. If there is only one main product, product can be used as unit of measurement;
If a variety of products are produced, it is difficult to use output of one of products as the overall unit of measurement. In this case, representative product measurement method can be used.
Select product that represents professional direction of enterprise, product with the largest product of output and working hour quota as representative product, and other products can be converted to representative product using conversion factor. Calculation formula of conversion system Ki is as follows:
In formula: Ki——conversion factor of i product;
ti—time quota of i product;
to——represents time quota of product.
Sometimes enterprises use output to calculate production capacity with low accuracy and can not reflect production capacity well, then input can be used as unit of measurement, such as total number of equipment, installed capacity and so on.

(2) Unit of measurement is amount of raw materials processed

Some enterprises use a single fixed raw material to produce a variety of products. In this case, it is more appropriate to use number of raw materials processed annually as unit of measurement for production capacity.
Production characteristics of such enterprises are often decomposing, that is, using one main raw material to decompose to produce a variety of products.

02 Identify factors affecting productivity

(1) Product factors

Product design has a huge impact on production capacity. If similar products are produced, ability of operating system to produce such products is greater than production capacity of subsequent products that are different.
In general, the more similar output, the more likely it is to standardize its production methods and materials, allowing for greater production capacity.
In addition, specific product mix of design must also be considered, as different products have different yields.

(2) Personnel factors

Tasks that make up a job, types of people involved in activity, training, skills and experience required to perform a task have a significant impact on potential and actual outputs.
In addition, there is a direct link between motivation, absence, rollover of people involved and productivity.

(3) Facility factors

Design of production facility, including size of plant and space left for scale-up, is also a key influencing factor.
Site factors, including transportation costs, distance to market, labor supply, energy and room for expansion, are also important factors. Likewise, layout of work area also determines smooth execution of production operations.

(4) Process factors

Product process design is an obvious factor that determines production capacity. Whether process design is reasonable or not affects product quality. If product quality is not up to standard, it will increase product inspection and rework work, resulting in a decline in production.

(5) Operational factors

An organization's scheduling problems, inventory reserve decisions, delays in shipments, desirability of purchased raw materials and components, quality inspection and process control, all have an impact on effective production capacity due to conflicting production capacities of different equipment or conflicting job requirements. .

(6) Other factors

Product standards, especially minimum product quality standards, can limit options for managers to increase and use production capacity. For example, companies often reduce effective production capacity in order to meet pollution standards for products and equipment.

03 Calculate production capacity of batch processing enterprises

In this type of enterprise, organization of production department adopts principle of process specialization, input and output of products have a long interval and obvious periodicity. Their production capacity calculation is closely related to division of workshops and teams based on principle of process specialization.
injection molding factory 

(1) Calculate production capacity of a single equipment

Since processed parts are not a single variety, number can reach hundreds or thousands.
All parts have different shapes and sizes, different processing steps, and different processing times. At this time, output cannot be calculated, but only effective processing time that equipment can provide, which is called machine time. Calculated as follows:
Among them: Ho - annual system working hours;
η——Planned utilization rate of working time of equipment system;
θ——Planned repair downtime rate of equipment;
S - Equipment downtime for planned repairs.

(2) Calculate production capacity of team

Workshop team is the smallest production unit. Each team is equipped with a certain number of equipment with same processing technology, but their performance and capacity are not necessarily same.
Therefore, calculation of production capacity of team starts from a single device, and then integrates production capacity of these devices for calculation.
If processing technical parameters of all equipment in the team are not very different, sum of time of all equipment is production capacity of team.
If technical parameters are very different, then it is necessary to count machine hours of equipment with different parameters, and focus on checking whether processing capacity of equipment for some large workpieces can meet production requirements.

(3) Determine workshop capacity

Since processing object of team is parts, their capacity should be measured in machine hours, while production object of workshop is often number of products or parts, so its production capacity should be measured in output. Conversion between man-hours and output is relatively simple.

(4) Determine factory production capacity

Production capacity of factory can be determined according to capacity of main production workshop, and workshop with insufficient capacity can be solved by adjustment measures.

04 Calculate production capacity of an assembly line enterprise

(1) Calculate production capacity of assembly line

Production capacity of assembly line depends on production capacity of equipment in each process, so it is calculated from a single device. Calculated as follows:
M single = He/ti
In formula: M single - production capacity of a single equipment;
He——single equipment planning period (years) effective working time (hours);
ti——Time quota for processing a single product on this equipment (hours/piece).
If a process is undertaken by one piece of equipment, production capacity of a single piece of equipment is process capability. When process is undertaken by N sets of equipment, process production capacity is M single × N.

(2) Determine production capacity of workshop

If it is a manufacturing workshop, it has both a part processing line and a component assembly line. At this time, its production capacity should be determined by capacity of assembly line.
Even if processing capacity of individual parts is lower than assembly line capacity, it should be determined according to this principle.
If it is a parts processing workshop, each part has a dedicated production line, and all parts are matched with products of company, then production capacity of workshop should depend on capacity of production line with the smallest production capacity.

(3) Determine production capacity of enterprise

Due to large differences in processing objects and processing techniques between workshops, performance of selected equipment is very different, and production capacity is inconsistent. Therefore, production capacity of basic production workshop is usually determined according to leading production link.
When production capacity of basic production workshop and auxiliary production department is inconsistent, enterprise should be determined by production capacity of basic production workshop.
Calculating production capacity is a necessary step to do a good job in production capacity planning, and it is also an issue that enterprises must pay attention to.
By calculating production capacity of an enterprise, it is possible not only to know one's actual capacity, but also to find out bottlenecks and excess links in production process, to provide basic information for scientific and rational planning of production capacity.

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