The 4 Ps of service design actually refers to this 4 Ps: People, Products, Partners, and Processes. All of these are supposed to help create the type of strategy that will be done in order to improve the type of service that will be given to people. In other words, the 4 Ps refer to the major areas to check out in order to provide effective service management to the customers.
Great service will prompt people to go back to the same place and try out other products that the company offers. Some people often confuse this with the 4 Ps of service strategy which is completely different.