In MTO systems due to a wide variety of
products, low amount of standard products and
the lack of possibility of appropriate forecasts,
the production planning is more complicated
than MTS systems. The arrival times of orders
are stochastic over time and each new order often
has a significant effect on profit and market share of
company. Therefore, MTO companies need an
efficient decision-making structure at the order
entry stage in which the company can select an
appropriate combination of the arriving orders.
This combination must lead to the increase of
the profit and the market share of the company
significantly. In this paper, a new decisionmaking
structure is proposed to select this
combination.
The proposed structure contains the following
advantages in comparison with the previous research:
In the proposed structure, all affected parties of
the supply chain are taken into account to
manage and plan the arriving orders efficiently.
These parties consist of customers, the MTO
company, subcontractors, and suppliers. The
parties are considered in an appropriate hierarchy
to take decisions that are acceptable for all
parties.
Since undesirable orders are identified and
rejected through some special criteria, it leads
to better planning and control for the rest of the
arriving orders and also can prevent the IP1
model from infeasibility.
Generating different alternatives to compute
price and delivery time of each arriving order.
These alternatives increase the chance of acceptance
of the orders because customers face with
different values and can select one, which is
appropriate for them. In brief, this contribution
facilitates the negotiation process for the MTO
company and customers that is an important
stage in the acceptance/rejection decision (Calosso
et al., 2003, 2004).
The use of two developed mixed-integer programming
models in the structure to determine
price and delivery time of the accepted orders
and also to select the optimal combination of
subcontractors and suppliers. These models help
the MTO system to manage the arriving orders
efficiently.
Moreover, the following directions can be considered
for future research:
So far, extent research has been done on the job
release and the dispatching mechanisms as short
term planning in MTO environments. Aggregation
of the order entry and short-term planning
stages within a hierarchical production planning
structure in MTO companies will certainly
improve the performance of the MTO company.
In this regard, the hierarchical production planning
structure includes three main stages, i.e., the
order entry stage, the order release stage and the
dispatching stage. This issue is on our research
line.
Nowadays, besides price and due date criteria,
the quality of final products is also important for
the customers. Since suppliers and subcontractors
have a great effect on the quality of final
products, hence quality criterion should be added
to the criteria set to select the best set of suppliers
and subcontractors.
The proposed mathematical models can be
improved in different ways. For example, the
assumption of providing each raw material
and workload by only one selected supplier
and subcontractor can be neglected in the IP2
model. In such a case, in addition to the selection
of the best combination of supply chain
partners, the purchased amount of raw material
and workload from each partner is also