Deploying rails app to heroku

Question

I have deployed my app to heroku. Everything was ok. When i go to the rails app, sometimes, ie at some links it crashes. The error message says (We are sorry but something went wrong.Checking error logs i found:

 SELECT "staffs".* FROM "staffs" ORDER BY "staffs"."name" ASC 2015-03-31T06:41:33.006245+00:00 app[web.1]: PG::UndefinedTable: ERROR: relation "staffs" does not exist 

And i am sure i have migration that creates my staffs table. My app works fine in development but in production i have such problems. (i use sqlite in development and PG in production. What can be causing such problems? Here is my migration for staffs:

 class CreateStaffs < ActiveRecord::Migration def change create_table :staffs do |t| t.string :name, null:false t.string :responsibility t.timestamps null: false end end end