Success with job shop operations (Part I) – How to increase throughput


sample_ProcessJob shop operations involve the conversion of inputs to outputs in environments characterized by low volume orders, custom builds, scarce machines, scarce people and scarce materials.

Balancing supply with demand is key for any business – job shop operations are no different but there are a number of unique challenges in job shop operations not present in high volume manufacturing operations.

Given a specific infrastructure (e.g. premises, equipment, people, access to materials, and access to working capital) in the presence of a steady stream of orders, the key to higher profits is to make efficient use of this infrastructure.

At the end of the day it’s all about throughput and quality control.

If machines and people are not kept busy you have under capacity whereas overloading stresses the organization and can cause quality to suffer (e.g. machines break down, people make mistakes), so it seems logical that keeping things running at a reasonable pace with a focus on minimizing time gaps between steps is likely to produce the desired result (i.e. good use of infrastructure).

Putting these ideas into practice for job shop operations requires two initiatives:

  1. When orders come in, processes need to be immediately mapped. It has to be easy and quick. (i.e. graphically map out the steps, identify the resource needs at each step along with any forms needed to collect data and to provide evidence of completion of work).
  2. Roll out each mapped process as a template for the order to a 3-tier RALB (resource allocation, leveling and balancing) scheduling environment and let the environment do most of the heavy lifting;

Here’s how throughput can be increased.

Level 1 Scheduling

The environment auto-posts steps to the attention of the right people using logic connections in your maps, plus resource tags at steps.

Workers perform steps, fill in any forms at these steps, and commit steps.

Soon as a step is committed process map logic kicks in again posting the next-in-line step to the attention of the appropriate workers (no unwanted time delays between steps).

Level 2 Scheduling

Let’s do a reality check here – It’s fine to eliminate time gaps between the time tasks are committed and the posting of next-in-line-steps.

However, workers rarely focus on one order at a time.  (i.e. machines may be busy, materials may be on backorder, a needed assembly may not be ready for consolidation with another one) so we need to let workers micro-schedule their own work, going off one order to another and then later returning to a suspended order.

 Level 3 Scheduling

Next we have imbalances that are the result of any number of things (changing customer priorities, failure of an assembly at QA, receipt of a change order) any of which can result in a need for supervisors to level and balance workload across machines and people.

It’s hard to argue against the logic of the 3-tier scheduling approach to workflow/workload management for job shop operations.

What’s in your scheduling algorithm?

 

(Part I) – How to increase throughput http://wp.me/pzzpB-ra

(Part II) – How to collect data at workflow steps http://wp.me/pzzpB-rf

(Part III) – How to put decision support in-line http://wp.me/pzzpB-rm

(Part IV) – Interoperability  http://wp.me/pzzpB-rq

About kwkeirstead@civerex.com

Management consultant and process control engineer (MSc EE) with a focus on bridging the gap between operations and strategy in the areas of critical infrastructure protection, healthcare, connect-the-dots law enforcement investigations, job shop manufacturing and b2b transactions. (C) 2010-2017 Karl Walter Keirstead, P. Eng. All rights reserved. The opinions expressed here are those of the author, and are not connected with Jay-Kell Technologies Inc, Civerex Systems Inc. (Canada), Civerex Systems Inc. (USA) or CvX Productions.
This entry was posted in Business Process Improvement, Business Process Management, Job Shop Operations, Productivity Improvement, R.A.L.B., Scheduling and tagged , , , , . Bookmark the permalink.

One Response to Success with job shop operations (Part I) – How to increase throughput

  1. francois de villiers says:

    Sensible scheduling logic and simple enough for everyone to understand. I would love to know the details of how this works in practice.

    Like

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