Under what situations should a push strategy would be used? what about a pull strategy?

Push strategy would be used when a vendor advertises its product to gain audience awareness.A push based supply chain strategy is usually suggested for products with low demand uncertainty, as the forecast will provide a good indication of what to produce and keep in inventory, and also for products with high importance of economies of scale in reducing costs.
             A pull based supply chain strategy, usually suggested for products with high demand uncertainty and with low importance of economies of scales, which means, aggregation does not reduce cost, and hence, the firm would be willing to manage the supply chain based on realized demand.