Next generation Optimization with ODH

Robert Ashford Optimization Direct

The petrochemicals, energy and metals industries have used mixed integer programming (MIP) planning and investment models to run their businesses for decades. Increasing hardware and software capabilities have taken these models to shorter term scheduling and logistics problems and now the technology is used across all endeavours from agriculture to aerospace, from mining to manufacturing, from scheduling to strategy, from railways to retail.

However model size and complexity is growing as short term decisions, detail and more complex global operations need to be considered. These are supported by a growing availability of accurate data and many stretch the MIP optimization software technology and hardware to the limit.

ODH was developed by Optimization Direct and born from the need to get good solutions to highly complex satellite scheduling models. These models were so large, complex and numerically challenging that established technologies failed to deliver anything useful. A new approach was needed and ODH was developed. Now this next generation optimization technology is used in scheduling, communications, supply chain and logistics extending the footprint of optimization across the full range of industrial and organisational activities.

It is particularly successful on models which naturally decompose into separate entities such as time-periods, production lines, manufacturing centers and so forth. It principally works by splitting the entire problem into a sequence of smaller sub-models which can be solved simultaneously on separate processors or cores. ODH is effective at exploiting the 8 or 12 cores commonly available on modern servers.

ODH|CPLEX is an embedding of the ODH engine inside the world’s leading MIP optimizer, IBM CPLEX. It brings the advantage of ODH – finding good solutions to difficult models – to CPLEX which computes an improving best bound and closes the optimally gap to give solutions of proven quality.

The ODH technology works hand-in-glove with CPLEX from the ODH engine using CPLEX to solve the sub-models to exchanging solution and bound information with the main CPLEX solve of the full model. Since it runs in concurrent separate threads it needs at least 12 cores to run most effectively but may still bring benefits to 4 core configurations.

The ODH decomposition method can be tailored to the model structure for improved performance and when used within a modelling system such as AIMMSTM, it can use the symbolic algebraic model structure to accelerate optimization.

Contact Optimization Direct to find out how next generation optimization with ODH can benefit your organisation.