{"id":1466,"date":"2012-04-21T10:33:54","date_gmt":"2012-04-21T10:33:54","guid":{"rendered":"http:\/\/www.saasoft.com\/blog\/?p=1466"},"modified":"2012-04-21T10:33:54","modified_gmt":"2012-04-21T10:33:54","slug":"the-bucket-brigade-fire-fighting-service","status":"publish","type":"post","link":"https:\/\/hcse.blog\/?p=1466","title":{"rendered":"The Bucket Brigade Fire Fighting Service"},"content":{"rendered":"

\"\"<\/a>Fire-fighting is\u00a0a behaviour that has a long history, and before Fireman Sam\u00a0arrived on the scene we had the\u00a0Bucket Brigade.\u00a0 This was a people-intensive process designed to deliver water from\u00a0the nearest pump, pond or river\u00a0with as little risk, delay and effort as possible. The principle of a bucket-brigade is that a chain of people forms between the pump and the fire\u00a0and they\u00a0pass buckets in two directions – full ones from the pump to the fire and empty ones from the fire back to\u00a0the pump.<\/p>\n

A\u00a0bucket brigade is\u00a0useful metaphor for\u00a0many processes and\u00a0an\u00a0Improvement Science Practitioner (ISP) can learn a lot from exploring its behaviour.<\/p>\n

First of all the number of steps in the process or stream\u00a0is fixed because it is determined\u00a0by the distance between the pump and the fire. The time it takes for a\u00a0Bucket Passer to pass a bucket to the next person\u00a0is\u00a0predictable \u00a0too and it is this cycle-time<\/em>\u00a0that determines\u00a0the\u00a0rate\u00a0at which\u00a0a bucket\u00a0will move along the line.\u00a0The fixed step-number and fixed cycle-time implies that the time it\u00a0takes for a bucket to pass from one\u00a0end of the line to the other is fixed too. It does not matter if the bucket is empty, half empty or full – the delivery time per bucket is consistent\u00a0from bucket to bucket. The outflow however is not fixed – it\u00a0is determined by how full each bucket is when it reaches\u00a0the end of the line: empty buckets means\u00a0zero flow, full buckets means maximum flow.<\/p>\n

This implies that the process is behaving\u00a0like a\u00a0time-trap<\/em> because\u00a0the delivery time and\u00a0the delivery volume (i.e. flow) are independent.\u00a0Having bigger buckets or fuller buckets\u00a0makes no difference to the time it takes to traverse the line but it does influence the outflow.<\/p>\n

Most\u00a0systems\u00a0have many processes that are structured just like a\u00a0bucket brigade: each step in the\u00a0process contributes\u00a0to\u00a0completing the task before handing the part-completed task on to the next step.<\/p>\n

The four dimensions of improvement are Safety, Flow, Quality and Productivity and we can see\u00a0that, if we are not\u00a0dropping\u00a0buckets, then the safety, flow and quality are fixed by the design of the process. So what can we do to improve productivity?<\/p>\n

Well, it is evident\u00a0that the\u00a0time it takes to do the\u00a0hand-off adds to the cycle-time of each\u00a0step. So along comes the Fire Service\u00a0Finance Department\u00a0who sees time-as-money and they work out that the\u00a0unit cost of\u00a0each step\u00a0of the\u00a0process\u00a0could be reduced by\u00a0accumulating the jobs\u00a0at each stage and then handing them off as a batch – because the time-is-money and the cost of the\u00a0hand-off\u00a0can now be\u00a0shared across several buckets. They conclude that the\u00a0unit cost for the steps\u00a0will come down and productivity will go up –\u00a0simple maths and intuitively obvious in theory – but does it actually work in reality?<\/p>\n

Q1: Does it\u00a0reduce the number of\u00a0Bucket Passers? No. We need just as many as we did before.\u00a0What we are doing\u00a0is replacing the smaller buckets with bigger ones – and that\u00a0will\u00a0require\u00a0capital investment.\u00a0 So\u00a0when our Finance Department\u00a0use\u00a0the lower unit cost as justification then\u00a0the bigger, more expensive buckets start to look like a good financial\u00a0option –\u00a0on paper. But looking at the\u00a0wage bills we can see that they are the same as before so this raises a question: have the bigger buckets\u00a0increased the flow or reduced the delivery time? We will need a tangible, positive and measurable \u00a0improvement in productivity to\u00a0justify our capital investment.<\/p>\n

To summarise:\u00a0we have the same number of Bucket Passers working at the\u00a0same cycle time so there is\u00a0no improvement\u00a0in how long it takes\u00a0for the water to reach the fire from the pump! The delivery time is unchanged. And using bigger buckets implies that the pump needs to be able to work\u00a0faster to fill them in one cycle of the process – but\u00a0to minimise\u00a0cost\u00a0when we created the\u00a0Fire Service we bought a pump with just enough average flow capacity\u00a0and it cannot be made to increase its flow. So, equipped with\u00a0a\u00a0bigger bucket\u00a0the first Bucket Passer\u00a0has to wait longer for\u00a0their bigger bucket\u00a0to be filled before passing it on down the line.\u00a0 This implies\u00a0a longer cycle-time for the first step, and therefore also for every step in the chain. So the delivery-time\u00a0will actually get longer<\/em> and the flow will stay the same – on average. All we have appear to have achieved is a higher cost and longer delivery time – which is precisely the opposite of what we intended. Productivity has actually fallen!<\/p>\n

In a state of\u00a0 near-panic the Fire Service\u00a0Finance Department decide\u00a0to measure\u00a0the utilisation of the Bucket Passers and discover that it has\u00a0fallen which must mean that they have become lazy! So a\u00a0Push Policy is imposed to make them work faster – the Service cannot afford financial inducements – and threats cost nothing.\u00a0The result is that in their haste to avoid penalties\u00a0the bigger, fuller, heavier buckets get fumbled and some\u00a0of the precious water is lost\u00a0– so less reaches the fire.\u00a0 The yield of the process falls and now we have a more expensive, longer delivery time,\u00a0lower\u00a0flow process. Productivity has fallen even further and now the Bucket Passers and Accountants are at war. How much worse can it get?<\/p>\n

Where did we go wrong?<\/em><\/p>\n

We made an error of omission.\u00a0We omitted to learn the basics of process design before attempting to improve the productivity of our time-trap dominated process!\u00a0 Our error of omission led us to\u00a0confuse the step, stage,\u00a0stream and system\u00a0and we incorrectly used stage metrics (unit cost and utilisation) in an attempt to improve\u00a0system performance (productivity). The outcome was\u00a0the exact opposite of what we intended;\u00a0a line of\u00a0unhappy Bucket Passers; a frustrated Finance\u00a0Department and\u00a0an angry\u00a0Customer whose house burned down because\u00a0our Fire Service\u00a0did not deliver enough water on time. Lose-Lose-Lose.<\/p>\n

Q1: Is it possible to improve the productivity of a time-trap design?<\/p>\n

Q1: Yes, it is.<\/p>\n

Q2: How do we avoid making the same error?<\/p>\n

A2: Follow the\u00a0FISH<\/a>\u00a0.<\/p>\n

\"\"\"\"\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

Fire-fighting is\u00a0a behaviour that has a long history, and before Fireman Sam\u00a0arrived on the scene we had the\u00a0Bucket Brigade.\u00a0 This was a people-intensive process designed to deliver water from\u00a0the nearest pump, pond or river\u00a0with as little risk, delay and effort as possible. The principle of a bucket-brigade is that a chain of people forms between … <\/p>\n

Continue reading “The Bucket Brigade Fire Fighting Service”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17,18,30,32,43,45],"tags":[],"class_list":["post-1466","post","type-post","status-publish","format-standard","hentry","category-examples","category-finance","category-operations","category-productivity","category-why","category-what"],"_links":{"self":[{"href":"https:\/\/hcse.blog\/index.php?rest_route=\/wp\/v2\/posts\/1466","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hcse.blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hcse.blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hcse.blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hcse.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1466"}],"version-history":[{"count":0,"href":"https:\/\/hcse.blog\/index.php?rest_route=\/wp\/v2\/posts\/1466\/revisions"}],"wp:attachment":[{"href":"https:\/\/hcse.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1466"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hcse.blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1466"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hcse.blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1466"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}