 The downside of MRP and Push strategy is that it usually leads to larger stocks in the supply chain.That is why Push is regarded as the opposite of lean production because lean production involves the Pull strategy which means that any part should only be produced if there is a certain demand for it and therefore WIP will be small.Push strategy is when MRP is used also to schedule production orders for semi-finished products (assemblies) based on the forecasted demand of the finished product.