When the designer designs the elements of the machine or the complete machine, they have to consider several important parameters. Here are some of the important factors to be considered while doing machine design.

●      1) Cost: Cost has always been the major factor of consideration while designing the machine elements or machine and in this age of competition it has become more important. The best machine design is the one which helps get the finished product with all the major functionalities and highest possible quality at the lowest possible cost. Gone are the days when expensive and bulky materials were used for making the machine elements.

●       2) High output and efficiency: Earlier machines used to be very heavy and consume lots of power. Now the trend is of full functional machines consuming low power and giving high output in terms of the number of the of products manufactured. Some computer controlled machines can manufacture the components very fast and are highly efficient.

●      3) Strength: The machine elements or the machine should be strong enough to sustain all the forces it is designed for so that it is not damaged or permanently deformed during its life time. Right at the time of the designing the machine the designer should consider the force machine can be applied to and consider all the relevant factors that could affects its life.

●      4) Stiffness or rigidity: The machine should be rigid enough so that under the effect of applied forces for which it is designed there is no deformation of the machine or machine elements beyond the specified limits. If there is excessive deformation, there are chances of the failure of the machine elements and the whole machine.

●      5) Wear resistance: Wear is the removal of the material from the metallic surface when two surfaces rub with each other. If there is more removal of the material, the component will become weaker and eventually break. The wear of the contacting surfaces can be reduced by the lubrication of the surfaces, increasing the strength or the hardness of the working surfaces. The effect of wear can also be reduce by increasing the surface, so that during the lifetime of the mating machine elements they will not fail even if there is some wearing between them.

●      6) Lubrication: Lubrication between the two mating surfaces of the elements of the machine help reducing friction between them and wearing of the two surfaces, which results in the increase in life of the components of the machine.

●      7) Operational safety: For the safety of the operator of the machine, the hazard producing things from the machine should be eliminated and the design should confirm to the safety codes.

●      8) Ease of assembly: The elements of the machine should be such that the machine can be assembled very easily. For the mass production of the complex machines like automobiles, type writers etc, the concept of unit assemblies are common. The unit assemblies are assembled together to form the complete machine.

●      9) Ease and simplicity of disassembly: Like assembly, the disassembly of the machine also should be easy so as to easily carry out replacement of the parts, and repair and maintenance of the machine and machine elements.

●      10) Ease and simplicity of servicing and control: The machine and its element should be simple enough so that very little maintenance and servicing is required. The repair and maintenance of the machine should be easy and cheap and simple replacements should be available.

●       11) Light weight and minimum dimensions: The machine elements and machine should be strong, rigid and wear resistant with minimum weight and least dimensions. This can be achieved by using light weight rolled sections and hardening the metals. Using high strength grades of cast iron and light alloys can further help getting light materials and minimum dimensions of the machine elements. Improving the design in this direction is very important.

●      12) Reliability: The reliability of the machine is a very important if the machine has to find the huge market in the business.

●      13) Durability: The longer the life of the machine more it develops the reputation of being the dependable machine and more will be its sale. Hence the right at the time of designing reliability and durability should be given priority. For this the machine should be designed for least maintenance requirements and long-life.

●      14) Economy of performance: For the proper economic performance of the machine correct mechanical, hydraulic, thermodynamic and other principles should be applied while designing the elements of the machine and the whole machine.

●      15) Accessibility: The machine elements and machine the whole should be easy to handle and access.

●      16) Processability: The shape and the materials for the elements of the machine should be such that they can the processing costs and labor costs are lowest possible.

●      17) Compliance with state standards: Following the standards makes designing easier and availability of various parts faster and easier.

●      18) Economy of repairs and maintenance: While designing the machine elements and machine the designing should be such that least amount of repairs and maintenance will be required for the machine.

●      19) Use of standard parts: There should be maximum possible standard parts in the design of the machine. This will help reduce the cost of the machine and ensure easy availability of the parts. With standard parts the design can be modified easily.

●      20) Use of easily available materials: Materials selected for the machine elements during the design should be available easily and lowest possible costs.

●      21) Appearance of the machine: While designing the machine the aesthetics and ergonomics of the machine should be given due consideration without affecting its functionality.

●      22) Number of machines to be built: Designing of the machine will depend a lot on the number of machines to be manufactured. If few numbers of machines are to be manufactured then expensive materials and high production costs can be considered, but for the mass production economy of the machine should be top priority.