How should the production capacity of SMT factory be calculated?
Jan 25, 2024
Production capacity (capacity) is an important issue for all businesses and at all levels of the business. Production capacity refers to the maximum capacity that a working unit can handle at full capacity.
 
The unit of work here can be a plant, department, machine or individual worker. When calculating production capacity, the following should be grasped:
 
01 Determine the calculation unit for production capacity
 
Due to the wide range of enterprise types, the products and production processes of different enterprises vary greatly. Before calculating production capacity, the unit of measurement of the enterprise's production capacity must be determined.
 
(1)Input and output volume
 
Production capacity is closely related to input volume and output volume. Different enterprises can choose input volume or output volume as the measurement unit of production capacity according to their own nature and other circumstances.
 
When an enterprise uses output as the unit of measurement, it needs to consider how many types of products the enterprise produces. If there is only one main product, that product can be used as the unit of measurement;
 
If a variety of products are produced, it is difficult to use the output of one of the products as the overall measurement unit. In this case, the representative product measurement method can be used.
 
Select the product that represents the professional direction of the enterprise, the product with the largest output and working hours quota as the representative product, and other products can be converted to representative products using the conversion coefficient. The calculation formula for conversion system Ki is as follows:
 
Ki=ti/to
 
In the formula: Ki——conversion coefficient of product i;
 
ti——time quota for product i;
 
to - represents the time quota of the product.
 
Sometimes enterprises use output volume to calculate production capacity with low accuracy and cannot reflect production capacity well. Then they can use input volume as the unit of measurement, such as the total number of equipment, installed capacity, etc.
 
(2) Use raw material processing volume as the unit of measurement
 
Some companies use a single fixed raw material to produce a variety of products. In this case, it is more appropriate to use the annual quantity of raw materials processed as the unit of measurement for production capacity.
 
The production characteristics of such enterprises are often decomposable, that is, using one main raw material, it is decomposed to produce a variety of products.
 
02 Determine factors affecting production capacity
 
(1) Product factors
 
Product design has a huge impact on production capabilities. If similar products are produced, the capacity of the operating system to produce such products is greater than the production capacity of subsequent products that are different.
 
Generally speaking, the more similar the output is, the more likely it is that its production methods and materials can be standardized, thereby achieving greater production capacity.
 
In addition, the specific product mix of the design must also be considered, because different products have different production volumes.
 
(2)Personnel factors
 
The tasks that make up a job, the various types of people involved in the activity, and the training, skills, and experience required to perform a task have a significant impact on potential and actual output.
 
In addition, there is a direct link between the motivation, absenteeism and turnover of the personnel involved and the production capacity.
 
(3)Facility factors
 
The design of the production facility, including plant size and room for expansion, is also a key influencing factor.
 
Site factors, including transportation costs, distance to markets, labor supply, energy and space for expansion, are also important. Likewise, the layout of the workspace also determines whether production operations can be executed smoothly.
 
(4) Process factors
 
Product process design is an obvious factor that determines production capacity. Whether the process design is reasonable affects product quality. If product quality is not up to standard, product inspection and rework will increase, resulting in reduced output.
 
(5)Operational factors
 
Scheduling problems, inventory reserve decisions, shipment delays, the desirability of purchased raw materials and components, and quality inspection and process control all arise in an organization due to conflicts in the production capacity of different equipment or conflicts in work requirements. Effective production capacity has an impact
 
(6)Other factors
 
Product standards, especially minimum product quality standards, can limit managers' options for increasing and using production capacity. For example, companies often reduce effective production capacity in order to meet pollution standards for products and equipment.
 
03 Calculate the production capacity of batch processing enterprises
 
In this type of enterprise, the organization of the production department adopts the principle of process specialization, and there is a long interval and obvious periodicity between product input and output. Their production capacity calculation is closely related to the division of workshops and teams based on the principle of process specialization.
 
  (1) Calculate the production capacity of a single piece of equipment
 
Since the parts processed are not of a single variety, the number can reach hundreds or thousands.
 
All parts have different shapes and sizes, the processing steps are also different, and the processing time is different. At this time, the output cannot be used to calculate, but can only be calculated using the effective processing time provided by the equipment, which is called machine time. Calculated as follows: 
 
He=Ho×η=Ho(1-θ)=Fo-S
 
Among them: Ho - annual system working hours;
 
η——Equipment system working time planned utilization rate;
 
θ——Equipment planned repair downtime rate;
 
S——Equipment planned repair downtime.
 
(2) Calculate team production capacity
 
The workshop team is the smallest production unit. Each team is equipped with a certain number of equipment with the same processing technology, but their performance and capabilities are not necessarily the same.
 
Therefore, calculating the production capacity of a team starts with a single piece of equipment, and then integrates the production capacity of these equipment into the calculation.
 
If the processing technical parameters of all equipment in the team are not very different, then the sum of the time of all equipment is the production capacity of the team.
 
If the technical parameters are very different, then the machine hours of equipment with different parameters should be counted separately, focusing on checking whether the equipment processing capabilities of certain large workpieces can meet production requirements.
 
(3) Determine workshop production capacity
 
Since the processing objects of the team are parts, their capabilities should be measured in machine hours, while for the workshop, its production objects are often products or component parts, so its production capacity should be measured in output.
 
(4) Determine factory production capacity
 
 
 
Factory production capacity can be determined based on the capabilities of the main production workshops. Workshops with insufficient capacity can be solved with adjustment measures.
 
 
 
04 Calculate the production capacity of assembly line enterprises
 
 
 
(1) Calculate assembly line production capacity
 
 
 
The production capacity of the assembly line depends on the production capacity of each process equipment, so the calculation starts from a single equipment. Calculated as follows:
 
 
 
M single=He/ti
 
  In the formula: M single - the production capacity of a single piece of equipment;
 
  He - the effective working time (hours) of a single piece of equipment during the planning period (year);
 
  ti - the time quota for a single product to be processed on the equipment (hours/piece).
 
 
 
If a process is undertaken by one piece of equipment, the production capacity of the single piece of equipment is the process capacity. When a process is undertaken by N pieces of equipment, the process production capacity is M units × N.
 
 
 
(2) Determine the production capacity of the workshop
 
 
 
If it is a manufacturing workshop, it has both parts processing lines and component assembly lines. At this time, its production capacity should be determined by the capacity of the assembly line.
 
 
 
Even if the processing capacity of individual parts is lower than the 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 the company's products, then the production capacity of the workshop should depend on the capacity of the production line with the smallest production capacity.
 
 
 
(3) Determine the production capacity of the enterprise
 
 
 
Since the processing objects and processing techniques vary greatly between workshops, the performance of the equipment selected varies greatly, and the production capacity is inconsistent. Therefore, the production capacity of the basic production workshop is usually determined according to the leading production link.
 
 
 
When the production capacity of the basic production workshop and the auxiliary production department are inconsistent, the enterprise should decide based on the production capacity of the basic production workshop.
 
 
 
Calculating production capacity is a necessary step for planning production capacity, and it is also an issue that enterprises must pay attention to.
 
 
 
By calculating the production capacity of an enterprise, it is not only possible to know its actual capacity and have a good idea, but also to discover bottlenecks and excess links in the production process, providing basic information for scientific and reasonable planning of production capacity.