Dear all , What are the Method of Costing for Plastic items Manufacturing Company ? How we can Reduce the cost ? Please advice me

To reduce costs said very general , we need more information about production for example : number of workers, machine, production quantity per day, etc. For the first you should check whole process one by one, observe workers

All costs of manufacturing process are capitalized to inventory on a systematic basis based on normal capacity.  

Acceptable methods of allocation of costs of manufacturing costs are absorption costing and Activity Based Costing.

Activity based costing is a method which best allocates fixed overhead based on actual production activity levels.   May be low volume product, but utilizes high labour or machinery set ups and costs., so must be allocated with the commensurate fixed overhead costs.

ABC also identifies less cost efficient products that perhaps should be considered for "discontinued line / product". 

Cost is depend on quality of the small nuts of plastic pieces from which plastic will made you can decrease the cost through changing the design or give economic order quantity to the vendors 

by dividing the total cost of production by the units produced.

First of all to reduce the cost we have to must reduce the stock inventory in hands Always well planned to deliver the required material in the time period ordered by the customer Timeline plays vital role in reducing the cost affect

You have to do more or manufacture , by big quantity you get less cost

Preferred method is absorption unless specific or special orders. To reduce cost1st implement standard costing and then find alternative or areas where Improvment required for example change required in size and style through CAD

Reducing the cost of the plastic means compromising on the quality. the best way to reduce overall  cost would be sourcing in the right quantity at the right time and from the right place. This will reduce wastage's. ABC is a good method to control quantity and cost. Try to reduce the lead time this will give you more opportunity to be in the market and eventually you will have more capital to innovate. Hence you will have more power to negotiate  with the suppliers. 

By finding some supplier that  gives also the standard specification of  your raw materials and gives low price than the current supplier.

the important one by controlling the process parameter

Plastic Industries is very sensitive Industreis, the main two reason of reduce  coast are your process control, good source of raw matriel, good storage of the raw matreil at the same time do not store more than you need at the production lines, also the set-up of your Machines and Equipment.