Abstract: Innovation is becoming a top priority for many firms with the aim to catering for customers' preferences. Hence, more and more firms are exploring new ways to improve their innovation competencies. The ‘crowdsourcing online design’ mode has been viewed as an effective and efficient tool to aid firms to enhance their strength in designing innovation, and it is a belief that this kind of online initiative can be supplementary to offline design and sharp the edge of firms' competition. However, to our best knowledge, the problem of how to seamlessly align upstream online crowdsourcing design with downstream production, in the scenario of supply chain, is still unaddressed. To solve this problem, a crowdsourcing supply chain consists of an offline designing firm, multiple online designers, a supplier and a manufacturer is studied to maximize the overall profit of the hybrid on/offline system, using mixed integer nonlinear programming (MINLP) approach.
The main work in this paper includes four parts. First, a stylized framework in which crowdsourcing supply chain is driven by order due-date and scheduled on regular time and overtime in the presence of Engineering to order (ETO) is proposed. Second, in this framework, a supply chain production model with ETO is formulated by taking into account that characteristics of offline customized design, and the determinants are identified is extended while implementing offline design/production system. Third, the above model to the hybrid on/offline model of crowdsourcing supply chain, and the impact of due-date and crowdsourcees on production operation is analyzed, and the switching conditions are devised for on/offline design. Finally, the particle swarm algorithm is employed to solve the above models. Through the numerical study the influence of design allocation between, online and offline, regular time and overtime, on the crowdsourcing supply chain profit, are explored respectively. Further, a sensitivity analysis is conducted to identify the critical parameters for positing and controlling the potential risks.
The results show that, when the upcoming order is in a small quantity, through hybrid on/offline customized design does not obviously and significantly reduce cost of crowdsourcing supply chain, whereas the advantage of cost-saving and risk-mitigating in crowdsourcing supply chain can be obtained with the increase in the number of order. Moreover, it also reveals that for online design order, it had better arrange at the beginning and end of periods. Meanwhile, online design orders should be avoided to allocate to produce at the regular time once scheduled for offline design, instead, it is more profitable to produce at the overtime. In addition, it is interesting to find that, by giving more reward to crowdsourcees, there is little effect on the change in entire supply chain cost, on the contrary, the incentives encourage more crowdsources to engage in crowdsourcing online design.

Key words: crowdsourcing supply chain, on/off-line, customized design, engineering to order