How can you reduce distribution costs without reducing the quality of service?

Reduce the purchase cost of the raw material, 

Increase production rate by reducing labour cost which means use automated machines for production

Thanks for invitation,

By using "The Centralized District Distribution" methodology.

Mr. samer zawde has valid points. will second him

packing is very important if your products can be packed is acceptable size of small boxes then you must have a box of bigger size designed to be able to put in the small boxes that your products can fit in in the biggest number possible and indeed you must choose the company that is most efficient and reliable and competitive and if your product cannot fit in small boxes then you you must choose the company that is most efficient and reliable and competitive and known in the transportation field

I guess that you mean the transportation costs when you are referring to distribution costs. With this assumption, this can be reduced without compromising on the quality of service by optimising the distribution network. There are many ways to optimise. One of the ways is to create clusters and use the hub and spoke model.