SuperPro Designer has found numerous applications in the consumer goods and food processing industries. Engineers at Kraft Foods have used it to optimize the manufacturing of specialty cheese and other dairy products. Engineers at P&G and Colgate-Palmolive use it regularly to design, evaluate, and optimize personal care products and processes. Scientists at Arla-Foods (Denmark) use it to design processes for the extraction of neutraceuticals from milk by-products.
A common application of SuperPro in the consumer goods and food processing industries is for reducing cycle times and increasing plant throughput. A simplified application of this type is described below. The example deals with shampoo manufacturing, but exactly the same problem appears in a variety of industries, including:
Cycle Time Reduction Example
- Formulation and packaging of pharmaceuticals.
- Baking processes for making cookies, bread, etc.
- Ice cream production.
- Preparation and bottling of beverages.
- Making and packaging of various food products (e.g., varieties of coffee).
- Preparation and packaging of various consumer products.
Process Description - Shampoo Making
The plant is equipped with two production lines (A and B) for making two types of shampoo (A and B). To make product A we charge water and an active ingredient into a mixing vessel (P-1/V-101), agitate the mixture, then transfer the mixture to an intermediate storage tank (V-102), which feeds the filling machine (FL-101). After a batch of A is completed, the two vessels (V-101 and V-102) are cleaned in place (CIP) and a batch of B is initiated using the same vessels. Please note that in this case the first step of Line B (procedure P-4) utilizes the same vessel (V-101) as procedure P-1 of Line A. The same is true for procedure P-5. It shares the same vessel (V-102) with procedure P-2 of Line A. A separate filling machine (FL-102) is available for handling product B. This may be a little confusing for those of you who are not very familiar with SuperPro Designer. When you model batch or semi-continuous processes in SuperPro, the icons on the screen represent processing steps (things that you do) and not necessarily unique equipment. Multiple processing steps can utilize the same piece of equipment at different points in time (as long as their cycle times cannot overlap).
This figure below shows the equipment utilization chart (generated by SuperPro Designer) for three consecutive batches (each color corresponds to a different batch). A plant batch includes a batch of product (A) and a batch of product (B). Note that V-101 and V-102 include two rectangles per batch. The first rectangle corresponds to making product (A) and the second to making product (B). FL-101 and FL-102 (the two filling machines) are used only once per plant batch.
The first set of arrows (on the left) indicate the making of a batch of (A). The set of arrows on the right indicate the making of a batch of (B). As it is clearly shown, as soon as material (A) is transferred out of V-101 and the vessel is cleaned, a batch of (B) is initiated in the same vessel. This is represented by the second rectangle of V-101 that is adjacent to the first. For V-102, there is a small gap (idle time) between the processing of material (A) and (B). That is the case because FL-101 is fast and completes the filling of one batch of (A) before a batch of (B) is ready to be transferred from V-101 into V-102.
The slow speed of FL-102 makes V-102 the current time (scheduling) bottleneck. Time bottleneck is the equipment that has the longest cycle time and determines the maximum number of batches per year or campaign.
Under these conditions, a new process batch is initiated every 4.5 h (in SuperPro this is called Plant or Recipe Cycle Time) and the plant produces on average 7,132 bottles of (A) and 10,190 bottles of (B) per day. It is assumed that the plant operates around the clock.
The figure below shows Operations Gantt chart (generated by SuperPro Designer) for the base case that displays the execution of the procedures and their operations in detail. For instance you can see that procedure P-1 includes the following operations: CHARGE-1 (for charging water), CHARGE-2 (for charging the active ingredient), AGITATE-1 (for mixing the materials), TRANSFER-OUT-1 (for transferring the contents from V-101 to V-102), and CIP-1 (for cleaning the vessel).
Note the synchronization of TRANSFER-OUT-1 in P-2 and the FILL-1 in P-3. That is the case because the mixture is being pumped out of V-102 while it is being packaged in FL-101. The duration of TRANSFER-OUT-1 in P-2 and consequently the occupancy of V-102 during P-2 depends on the process time (which, in turn depends on its throughput) of FL-101. Such details can readily be represented in SuperPro.
Also, please note that in SuperPro all cycle times are calculated by the program (you also have the option to set their values). Consequently, changes in batch size and operating parameters that affect the cycle time of some operations reflect automatically on the Gantt chart. This is a major difference between SuperPro and project management tools where you always have to specify the cycle times. In SuperPro, the Gantt chart is fully process driven.
Since V-102 is the current time bottleneck, the plant throughput can be increased by installing another tank of the same type. The flowsheet that follows represents this scenario. V-102 is dedicated to Line (A) whereas V-102-B is dedicated to Line (B).
The figure below is the Equipment Utilization Chart for scenario 1. With an extra storage tank (V-102-B), the plant cycle time drops to 3.8 h, in other words a new plant batch can be initiated every 3.8 h. The daily throughput of bottles (A) increases to 8,404 and that of (B) to 12,005, which represents an increase of almost 18%.
Under these conditions, V-101 becomes the new time bottleneck. If a new mixing vessel is added, the two production lines become totally independent (the cycle time of one does not depend on the other) and the plant throughput goes up further. The result is shown in the figures below (Scenario 2).
In this case each processing step has its own unique equipment (no sharing of equipment any longer). Under these conditions, Line (A) truly shines with an increase in throughput of almost 100%. The increase in throughput of Line (B) is 47.1%.
This is a very simple example that demonstrates how equipment sharing and cycle times of individual steps affect the overall throughput of a plant.
The true power of SuperPro can be experienced when you deal with considerably more complex processes that involve many more products and equipment items that are shared in a cyclical fashion. Please note that transfer lines also can be represented in SuperPro. For instance, if you have a bakery and transfer lines (that bring flour, sugar, and other ingredients) are shared among different product lines, SuperPro can be used to visualize and optimize their cyclical use.
All these questions can be readily answered with the use of SuperPro Designer. SuperPro also identifies resource bottlenecks, equipment size bottlenecks, and auxiliary equipment time bottlenecks. For more information, please go through the Overview page and download some of the literature on the subject.
- How can we increase throughput further?
- What would happen if we added another mixing tank?
- What would happen if we added another storage tank?
- How should we operate the extra tank, in parallel with the existing or in staggered mode?
And if you have any challenging debottlenecking questions, please do not hesitate to contact us.