Method

Process step methods specify how batches are processed and/or stored. They determine in detail the time relationships between inflow and outflow segments in and between process and tank batches. They are defined on a process step and reflected in process and tank batches. You can add their tags to planning board batches using your view settings.

 

Following are the standard methods.

• Batch Buffer - Process batch characteristics in batch buffer are the same as in batch process. Tank batch characteristics are the same as in-flow buffer, i.e. parallel inflow and outflow occurs after buffer time has been reached.
• Batch Inline Average - Batch inline average is similar to batch inline exact except for how flow pattern and rate matching are dealt with. Use inline average if you want to solve, use inline exact if you need detailed constraints such as a max rate, filling level, etc.
• Batch Inline Exact - (formerly Batch Inline) Batch Inline Exact is a variant of batch process. The specific characteristics of inline methods are described under flow inline. Note that the inflow segment of a process batch follows the outflow segments, even though the rates are not related. Use inline average if you want to solve, use inline exact if you need detailed constraints such as a max rate, filling level, etc.
• Batch Process - In the batch process method there is no simultaneous process inflow and outflow. Inflow and outflow rates are independent of each other and must be entered separately as a fixed rate or duration. Standing time is the period between the end of the inflow and the start of the outflow. If the process step is coupled, the tank batch following the process batch behaves identically to the final tank in a flow process.
• Flow Buffer - The only difference between flow process and flow buffer is that flow buffer allows simultaneous tank inflow and outflow. Buffer time is the minimum period between the start of tank inflow and the start of outflow. Slack occurs if the process is not on its latest time.
• Flow Inline Average - Often inline is used to synchronize two stages. You can use Flow inline average for that. The difference between flow inline average and exact is how flow pattern and rate matching are dealt with. Use inline average if you want to solve, use inline exact if you need detailed constraints such as a max rate, filling level, etc.
• Flow Inline Exact - (formerly Flow Inline) In flow inline, tank flow is (partly) simultaneous with, and is calculated from, tank inflow. The duration and start time of both the process batch and the tank batch of this method are therefore determined by the process batch of the following step. Filling time is the difference between the start time of the inflow and outflow of the process batch. Filling level is the level at which the tank is permitted to commence outflow. Initial rate is the rate with which that happens. This is also the maximum inflow rate: if during a certain period tank outflow exceeds the initial rate, the tank level will temporarily decrease. Use inline average if you want to solve, use inline exact if you need detailed constraints such as a max rate, filling level, etc.
• Flow Process - Flow process' main characteristic is that product is worked while flowing in and out of the process. Filling time is the time period between the start times of process inflow and outflow. The process' working rate is defined using a fixed outflow rate or duration. Tank inflow segments are based on the rate and duration of the preceding process batch outflow segments. Tank inflow is followed by minimum standing time, variable slack, and outflow. Outflow times and rates are based on tank batch inflow, but there is no simultaneous inflow and outflow.
• Flow Pushed - Flow pushed always follows directly on, and is driven by, flow source. This means that process batch inflow is determined by flow source tank batch outflow. The final tank batch has the same characteristics as the flow process method.
• Flow Pushed Buffer - This method is similar to the Flow Pushed method, but the final batch is a buffer tank instead of a fill-empty tank.
• Flow Source - The only difference between this and flow process lie in the behavior of the final tank batch. This always has outflow to a process batch with a flow pushed method, for which it dictates the start and end of inflow. Flow source can be scheduled as you want; flow pushed cannot because it always follows directly on flow source. The tank batch will often be what we call Virtual because the tank itself will not exist. Because of the direct relationship between the two methods, the link between the two processes will typically be a pipe or a conveyor belt, not a tank.