一个医院的血液样本分析中心请我从物流的角度分析他们的血液样本收集过程。他们感觉对于血液样本收集过程的效率是可以改善的。他们想验证这个想法，以及得到改善这个流程的可能性数据。
这个血液分析中心的主要工作是从病人处收集血液样本，分析样本，然后把结果报告给医生或者病人。有时候他们会建议病人关于他们可以服用什么药品，例如糖尿病的情况。有些病人去医院采集血液，但是大多数样本是在医院周边的血液中心的服务点采集的。这样，就会有大约30个不同的服务点可以让病人采集血样。
血液中心服务点的员工将服务点采集到的血样拿回实验室进行分析。作为额外服务，他们也会上门取样。一般情况下，员工们会在他们上班前或者下班后上门取样。这样就必须仔细的规划，因为不能让服务点的病人等待。可以想象，血样采集过程的重要条件是必须把血样及时地送回实验室，血样不能无限时地保存，必须即使送到实验室，否则不能进行分析。
可以看出这是一个相当复杂的物流过程，有如下的问题需回答：
- 是否有足够的服务点让病人采集血样？或者需要增加数量？
- 每个服务点的位置和营业时间怎样？
- 所有血样是直接送到实验室，还是首先收集到一个固定的地方？换句话说，是否需要一个中转站？
- 从员工角度来看，是否需要将上门取得的样本和在服务点取得的样本合并在一起？
运筹学将被用来解决以上问题。我们通过建立一个模型来分析血样采集过程以及分析和优化供应链。通过模型我们可以回答像设施的位置、规模以及服务哪些孤客的问题。透过模型我们发现建立一些中转站，将血样在送回实验室之前首先送到这些中转站，将会节省大约25％的时间，也即意味着节省了路程，减少了血液分析中心的成本。这些节省的时间可以用来采集更多的血样，同时提升了工作效率。
原作者：John Poppelaars
原网址：http://john-poppelaars.blogspot.com/2007/07/blood-sample-logistics.html
原文如下：
The diagnostic centre of a hospital asked me to analyze their blood sample collection process from a logistic point of view. They had a feeling that the performance of the collection process could be improved. They asked to verify this and also to provide a set of possibilities to improve the collection process.
The main activity of the diagnostic centre is to take blood samples from patients, analyze them and report the results back to the physician or patient. Sometimes they advise the patient with respect to the medicine they take, for example in the case of diabetes. Some of the patients come to the hospital to have a blood sample taken. Many of the blood samples however are taken at service locations of the diagnostic centre in the area around the location of the hospital. In this case there are about 30 different service locations where a patient can go, to have their blood sample taken.
The employees of the diagnostic center work at the service locations and take the blood samples from the service location to a laboratory to have them analyzed. As an extra service the employees also visits patients at home to take a blood sample. Currently the employees visit the patient at home before and after they work at the service location. This takes careful planning because patients at the service location must not be kept waiting. As you may guess an important condition in the collection process is to have the blood at the laboratory in time. Blood can not be kept indefinitely; it must be delivered on time to the laboratory, otherwise no analyses can be performed.
As you can see this is a rather complex logistic process. Many questions arise, such as
- Are there enough locations available for the patients to go to, or should the number be changed?
- What should be the opening times and the geographic position of each of these locations?
- Should all the blood samples be taken directly to the laboratory, or should they be collected first at specific places in the network. In other words should hubs be used?
- Should from an employees point of view the samples taken at the patient’s home be combined with the blood samples taken on the service locations of the diagnostic centre?
This is where Operations Research comes in. We analyzed the blood sample logistics with a model that we developed to analyze and optimize supply chains. With this model we can answer questions like where facilities should be situated, how large they should be and which customers should they serve. With this model we found that introducing a few hubs where blood samples are collected from the service locations before taking them to the laboratory saves about 25% of travel time of the employees. This saves time but also the distance traveled, which reduces the costs for the diagnostic center. This time saved can be used to take more blood samples boosting the workforce effectiveness as well.
