Managing Inventory on Blood Supply Chain

Nurhidayah binti Hamzah

• Abstract

There is unbalance the amount of blood demand and availability of blood for each component at Blood Transfusion Unit(BTU) in Indonesia.As the result,this component run into inventory shortage so management need to maintain the strategy of blood supply chain for patient.Purpose of this is to manage inventory on the blood component of Packed Red Cells to be the highest blood component requirement for patient in the case study.Managing inventory is done through several including forecasting method,safety stock and re order point.To manage inventory,this agency need to prepared 34 blood bags for safety stock and 76 blood bags for re order point.

• Introduction
• BTU to ensure the availability of blood,quality safety and blood donor information.
• BTU provided 7 blood component to distributed the patient involving whole blood,packed red cells,thrombocyte concentrate,fresh frozen plasma,washed erytrocyte,cryoprecipate and apheresis.
• This study aims for managing inventory on blood component of packed red cells(PCR).

Data of blood demand at BTU in years 2016 showed that there was unbalance the amount of blood demand and the availability of blood for each component.

• Inventory
• To determine the level composition of the stock of parts,raw materials and finished products.
• Requires to implement in order to maintain and control the production.
• Forecasting technique is implemented to predict future demand based on some predictor variables using historical time series data.Then result of forecasting technique used to perform production scheduling and control inventory.
• Safety stock to determine how much stock need during the grace period to meet the demand.
• Used to consider re order point in production scheduling.
• Necessary to determine how much the minimun level of inventory should to be considered that no shortage of inventory.

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• Blood supply chain
• The case study of blood components demand at BTU in Indonesia was the integration of several entities into a supply chain strategy.
• Classified 3 blood donors

1. Permanent blood donor

2. Blood donor volunteers

3. Blood donor substitute

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Figure 1 shows the business on Blood Transfusin Unit based on blood supply chain strategy

• Finding
• 3 stages

1.Forecasting demand

2.Safety stock

3.Re order point

• This mechanism is used as a reference in managing blood component of the packed red cell.

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1. Forecasting
1. Used 4 methods

i. moving average

ii. weighted moving average

iii. exponential smoothing

iv. exponential smoothing with trend

• Select the smallest error accuracy of each forecasting model.Then it done verification forecasting within the control limit by using tracking signal.

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• Positive tracking signal showed that actual value is grater than forecast,while negative value indicated actual value is less than predicted.

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• The result of this study was obtained that exponential smoothing with α=0.95 to the best forecasting method.

Figure 2 is trend data of demand and forecasting on Packed Red Cells

2.Safety stock and re order point

• This study required safety stock model to avoid the occurrence of lack of blood component of PRC in activities of bussiness process in BTU.
• Then continued to calculate re order point method to determine the minimum number of blood component for re-ordering.
• To determine the amount of safety stock,this agency established a risk of running out of inventory for this blood component of the by 5%.

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• Standart deviation (Z) was used approximately 1.65

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• Finally result of safety stock for packed red cell found 34 bags.Then the calculation of re order point for blood component on PRC found 76 bags.

3. Managing Inventory

• Result of this study showed that the number of safety stock for packed red cells was 34 bags and number of re order point was bags 76.
• This implication described that the inventory must has arrived at BTU on this number of 76 bags.
• Then this agency prepared for making the reservations again.

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Figure 3 managing inventory for Packed Red Cells (PRC)

• Discussion
• Research has done managing inventory through forecasting demand and re order point which it also considered the schedule of order blood component based on the safety stock approach.
• Arrange the production scheduling of blood componets of based on when orders must be received and how many safety stock should provided.
• Shortage of inventory must be avoided by BTU and they also should considerd viability of blood for each components.
• Managing inventory for blood components is very important to maintain the inventory in this agency safety and available.

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Data of supply blood component in 2018