In the modern industrial competitive context, manufacturers and product designers have a never-ending struggle, which is how to cut costs of manufacturing, and at the same time retain or better the quality of the products. Reduction of expense without being mindful of it usually results in poor performance, increased failure, and ruined brand image. Conversely, intelligent cost optimization plans have the potential of improving margins, reducing lead times and increasing product reliability simultaneously.
The trick is to know that reduction in the manufacturing cost is not concerned with the use of cheaper material or the omission of some crucial processes. It concerns design efficiency, streamlining the processes, aligning the supply chain, and minimizing wastes.
It is an elaborate reference on how to practically and successfully lower the cost of manufacturing without affecting the quality of product; be it in CNC machining, sheet metal fabrication, injection molding, welding or product assembly.
Understanding What Really Drives Manufacturing Cost
You need to have the sense of the origin of cost before you can reduce it. Manufacturing cost will usually be affected by:
- Material selection
- Part geometry complexity
- Machining time and cycle time.
- Surface finish requirement and tolerances.
- Assembly labor
- Tooling and setup time
- Rework and scrap
- Inefficiencies in supply chain.
Most businesses consider material cost only but in actual sense 70-80 percent of overall product cost is taken into consideration during design. That is, the cost control begins at the design level – not at the shop floor.
- Apply Design for Manufacturing (DFM) Principles Early
Design for manufacturing at concept stage is one of the most efficient approaches to cost reduction in manufacturing. When cost considerations are taken into account at the early stage of designing, engineers can eliminate a lot of frequent problems in production. Poorly designed components may lead to increased machining durations, to special tooling, to hard-to-fixture configurations, and to low non-conformance. Such issues do not only raise the direct manufacturing costs but also cause delays in production and variation of quality.
Rather, design should be made simple and practical. Elements that can be easily machined, easily attached and given clamps, symmetrical where practicable, and that can be used with standard tooling greatly simplify the production process. It is also important not to use unnecessary tight tolerances. Strict tolerances add needless time, inspection and scrap to the process with no functional value addition.
To illustrate, the number of excessive tolerances can be reduced significantly, and this can result in both a reduction in machining and inspection costs. Several parts are excessively tolerated without an apparent need. Features which directly affect performance, fit or safety should have tight tolerances only. Precision where it is needed can ensure the quality of the products allowing the manufacturers to save on the production cost.
- Simplify Part Geometry
Multifaceted geometry raises the CNC cycle time and tool wear, program writing, and inspection price.
To save money, and not quality:
- Avoid deep narrow pockets
- Minimize thin walls
- Get rid of unwarranted undercuts.
- Standardize corner radii
- Reduce feature count
A simpler design costs less to machine as well as enhances repeatability and stability of dimension.
Simplification enhances consistency of quality in most instances, as they have fewer chances of variation of dimensions.
- OptimizeMaterial Selection Strategically
The cost of material is a substantial component of the total cost of a product and smarter material choice is even more important. Designers should not blindly select high-grade alloys but need to consider whether these specifications are really needed. Such questions as the real need of extreme strength of application, whether or not aluminium can be substituted with steel, whether mild steel could be used instead of stainless steel in corrosion free conditions or whether the need to choose some standard stock sizes can reduce the amount of waste can result in significant savings without performance impact.
By selecting material that is easy to machine, readily obtainable in the market, has standard thicknesses or diameters and is somewhat compatible with tools already available in the market it is possible to save a lot of money in manufacturing. These options assist in reducing machining time, material waste and lessening the procurement procedures with the structural integrity that is required.
Nevertheless, downgrading in material has to be done with care. Proper mechanical, thermal and environmental analysis should support any change. Safety, durability as well as long term performance must not be compromised on cost reduction strategies. It is not to employ cheaper materials mindlessly but to utilize smarter materials in a responsible manner.
- Reduce Manufacturing Steps
Each new process step will add:
- Labor cost
- Setup time
- Risk of error
- Handling damage
- Look for ways to:
- Combine operations
- Eradicate secondary machining.
- Combine functionality within one installation.
- Reduce part count
As an example, part consolidation during assemblies can:
- Reduce fasteners
- Lower inventory cost
- Decrease assembly time
- Improve reliability
The smaller the number of components, the smaller the number of failure points – this increases the overall quality of the product.
- Standardize Components and Hardware
The custom fasteners, special bolt sizes, or fittings make procurement more complicated and slow down assembly activities. It may involve carrying the extra stock, multiple suppliers and frequent replacement of the tools on the shop floor. Rather than that, standardizing the sizes of the bolts, employing common types of thread, reducing the number of tools that have to be changed through the assembly process, and using easily sourced off-the-shelf parts can make production much easier.
The advantages of standardization are that the purchase costs are lower, the time spent in controlling the inventory is less, the assembly is quicker, and long-term maintenance is much easier. With the help of the widely found elements, manufacturers enhance the efficiency and consistency of their operations without affecting the performance or the reliability of products.
- OptimizeTolerances and Surface Finishes
Excessive tolerance is one of the largest cost drivers that are not well known.
- Tighter tolerances require:
- Slower machining speeds
- More precise tooling
- Additional inspection
- Higher rejection rates
On the same note, stating unneeded fine surface finishes raises the cycle time and cost of finishing.
To optimize:
- Use functional tolerance
- Apply GD&T strategically
- Tolerance to relaxation wherever possible.
Only where necessary, specify surface finish.
Note: All surfaces do not have to be machined to a mirror finish. It is only critical mating surfaces that are in need of high precision.
- Improve Production Efficiency and Cycle Time
Cycle time has a direct relationship with the cost of manufacturing.
Ways to reduce cycle time:
- Design for fewer setups
- Make sure that the tools are accessible.
- discourage interior complicated geometries.
- Designs conforming to a normal tooling.
- Empower automation where applicable.
Even a slight change in the cycle time per part would result in the substantial annual savings in medium-volume to high-volume production.
- Focus on Assembly Efficiency
Assembly labor is not considered as expensive.
To reduce assembly cost:
- Design self-aligning parts
- Minimize fastener count
- Take snap-fit or interlock.
- Make sure that there is proper orientation during assembly.
- Eliminate manual skill adjustment.
Efficient assembly minimizes the labor hours and minimizes the possibility of defects in assembly.
Quality when the assembly is easier for assembly will be better since there will be less variability.
Common Mistakes to Avoid
In attempting to lower manufacturing cost, the following errors are to be avoided:
- Replacing expensive materials with blindly switching.
- Elimination of critical quality inspections.
- Excessively tightening tolerances.
- Designing without seeking the advice of suppliers.
- Disregard of total lifecycle cost.
- Value should be added through cost reduction, and not reliability.
Final Thoughts
Persuasion to reduce manufacturing cost is best achieved when it is considered at an initial stage of product development. After the tooling has been completed and it starts production, design alterations are costly and disruptive. With the use of Design for Manufacturing principles, tolerances that are optimized, strategic material selection, simplification of processes, assembly efficiency at the concept stage can help companies reduce the costs of production by a substantial margin and yet, on top of it, the overall quality of the product can be improved, and in most cases, it is even higher.
The contemporary manufacturing industry has given the smart, collaborative, and endless optimization of systems as the competitive advantage. In the case of long-term profitability, do not forget that the lowest cost product is not the one that is merely cheaper to make and produce, but the one that can give you reliable quality at the lowest overall lifecycle cost.
