Problems of Existing Sequencing & Scheduling Systems

Typically the sequencing / scheduling process is a combination of manual effort using spreadsheets with support from computer based systems which mainly provide data analysis or provide initial, starting solutions.

These systems are often “hard wired”, which makes it difficult to keep pace with the changing business environment. For example, if a new car model is added, then many steps in the process may have to be changed. Or the introduction of a new color may require extensive reworking of the preferred color change matrix.

In a manual system it is difficult to consider all the constraints. The focus is on satisfying the higher priority constraints. Ignoring a constraint can lead to increased cost and loss of productivity. Consider the case of a supplier of leather interiors who can ship at most 100 sets per day. If this constraint is ignored then the daily requirement of leather interiors will be uneven which, in turn, will require that a buffer stock is maintained.

The repetitive task of manually sequencing several thousand units can introduce errors. This will also lead to increased costs and loss of productivity.

Each iteration of the sequence requires a significant amount of time – it can take from 1 to 3 days to make 1 sequence. Consequently:

  • Schedulers are not able to spend adequate time in communication and management of the sequencing process.
  • There is usually not enough time to generate different scenarios. A potentially good sequence may be ignored.
  • Similarly, there will be insufficient flexibility to respond to demand, production or supplier problems.

The net result is loss of flexibility and ability to respond quickly and a longer order to delivery lead time will be required to be able to deal with all the issues.

In conclusion, the competitive business environment and the need for quick response will push the complexity of the sequencing problem beyond the capability of legacy systems.