Several weeks ago I was discussing why a team was having trouble completing the work that they committed to delivering in a two week sprint. The team felt that one solution was to shift to a three week sprint, in other words to increase batch size be 50%. I asked the team to identify the problem that was causing the problem. While calendar time is a constraint, the bigger problem turned out to be the size of the user stories they were accepting. The team settled on trying an experiment of thinly slicing their user stories and reducing their sprint duration to one week. The combination of smaller stories enforced by an even tighter calendar constraint is a reduction in batch size. They have been at the new cadence for four weeks and have delivered on their commitments for last three sprints and have decided to continue the “experiment” for the foreseeable future. Cutting batch size is a solution that can work in manufacturing and in software development.

Part 1       Part 2       Part 3      Part 4      Part 5      Part 6      Part 7      Part 8    Part 9   Part 10   Part 11

Chapter 29

The plant shows incredible progress. Cutting the batch size in half led to less idle time for non-bottleneck resources, where idle time exists it has been spread out more diffusely, and work is flowing through the plant faster with lower overall inventory. However the classic measures, which focus on cost per step in the process rather than the system cost, do not show the improvement. The additional set ups have associated costs and effort which are a problem. Even through the plan is making more completed product with less inventory, the metrics do not show the improvement. Alex and his staff decide to change the measurement basis from 12 months to 2 months, with the rationale that the new process now in place is more endemic of how work will be done going forward. The decision is made despite the agreement that “Frost”, the Head of Accounting at Corporate, and Alex’s Boss, Bill Peach will not approve of the change.

Chapter 29 ends with Jons, the head of sales, bringing Alex a new order for 1,000 items. The client is offering the order to Alex’s company if they can deliver in a month. Jons believes that IF the plant can deliver, the client will shift all of its business to plant. The Alex and his team consider the order. They decide to not sacrifice everything else by not expediting the order, but if the client will accept a counter proposal of a 250 items every week for four weeks beginning two weeks after signing the order they can deliver. In order to deliver the order Alex and his team will need to order components for the item from another company (and have the parts shipped via air freight) and to cut the batch size in half again. The client likes the idea of the staggered deliver (they probably can’t use all 1,000 instantly either).

Chapter 30

The big order, or should we say four smaller orders, is moving well. The first couple of installments have been made on time and Alex’s staff foresee no issues with the rest. The continued reduction in batch size helped the plant meet its goals and has continued to improve the flow through the plant. The plant’s metrics show that inventory is down and throughput has doubled.

Alex receives two messages from Bill Peach. The first is praise for meeting the order and the second is a summons for a plant review. While preparing for the review, accounting discovers the change in the measurement basis (form 12 months to 2 months) that the plant implemented without permission and reacts badly. Lou, the plant accountant, is reprimanded and the numbers are restated. The plant has not met Bill Peach’s demand for a 15% increase.

Jons and Burnside, the client for the big order, arrive at the plant unannounced in a helicopter. They immediately head into the plant. After validating that the last shipment went out on time and without a quality problem Alex heads into the plant to find Burnside shaking every person’s hand he can find. The ability to deliver on time with great quality has made the plant a huge friend, and Jons confides to Alex that Burnside will sign a huge order next week. Jons goes on that with the plant’s quality and cycle time (the time between accepting an order to delivery) they will blow the competition away.

The chapter ends with Alex and Julie, Alex’s estranged wife, deciding to get remarried. All seems to be going well, but there are still 10 chapters left in the book . . .

The summary previous entries in the re-read of The Goal have been shifted to a new page (click here).   Also, if you don’t have a copy of the book, buy one.  If you use the link below it will support the Software Process and Measurement blog and podcast. Dead Tree Version or Kindle Version