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In the construction industry, delivery times of building materials are often delayed to fit the progress of construction, and therefore parts manufacturers are forced to hold extra parts inventory over the period of the delivery delay. To minimise the inventories, two production models, i.e., push and pull type production models can be widely considered. When production lead-time is short and length of delivery delay is long, a pull type may require smaller inventories to keep a certain service level, and a push type may require smaller inventories under the condition of longer production lead-time and shorter length of delivery delay. To examine performance of average inventory level under different system conditions, factors such as ratio of average length of delivery delay to production lead-time, length of production cycle, and coefficient of variation of demand are chosen to define different system conditions. As the performance measure, the ratio of push type inventory to pull type inventory is used in the comparison of the push and pull types, and a quantitative criterion of production model selection is presented.

With the dynamic changes of apparel fashion trends, it's becoming difficult to match demand using traditional inventory control models, without stock out or opportunity loss. To treat this problem, supply contract models were proposed in past one decade, arguing that it performs better compared to newsvendor in all condition. However, we found that in some conditions, the supply contract model with options unnecessarily perform better compare to traditional newsvendor model. This provides us an indication that when we introduce new business model, all the possible condition should be considered rather than considering average performance only. In this research, we compared the newsvendor model with our model, generating one by one demand distribution along with the possible parameter settings, and then examined the period of parameters that the option model can provide better performance. Furthermore, we found that the inferior performance is caused by the expense of purchasing options. Finally, we learned the important factors that play a major role in decision-making with the option model for fashion products.