Overview
The principle of lean is the elimination of all activities that do not add any value. We have extensive experience of applying these techniques in the service and logistics sector, in particular the back office and in warehouses and transport. The following are some of the techniques we have used successfully;
- standardised work and takt times
- gemba - going to the place of work and observing
- level scheduling and demand smoothing
- align resource with demand
- flexible workforce
- one-piece flow
- business modelling including current and future state mapping
- visual workplace and 5S
- KPIs and metrics
- A3s
- kaizen trackers
- 7 wastes in particular waiting and motion in the service sector
- mistake proofing
- Control charts, SPC, and six sigma
Standardised Work
This is the basic building block of lean. Standardised work sets the benchmark for how everyone should work, and is the baseline against which continuous improvement is measured.
Each process must be repeatable, everyone needs to follow the same standard steps for each process, everyone achieves the same output, and everyone completes the process in the same time.
Standardised work is achieved by going to the workplace, observing, and reducing every process to its simplest elements for review, once reviewed each step is recombined to create a standard process. This will be done repeatedly as part of the continuous improvement process.
Standardised work consists of three elements;
- inputs required (FTEs, tools/machines, and inventory)
- sequence in which the operator carries out each step
- takt time (time taken to complete the process)
Of these takt time is the most important because this is the measure that drives resource requirements, and is used when production levelling.
Production Smoothing
Production levelling or heijunka is one of the key lean concepts, it is the technique of ensuring every process has the same output and the same takt time. When all the individual processes are linked together to create a production line, production levelling minimises inventory and moves product through the process as quickly as possible, whilst also minimising workforce idle time. All of which makes the overall process as efficient as possible.
Practically this can be achieved in a number of ways;
- moving operational steps from the process to an earlier or later process in the overall production line
- increasing or decreasing the number of staff on a process
- multi-skilling staff so they can perform a number of processes
- changing the equipment used on a process
Within most environments there are typically multiple products or variants being produced on the same production line. This makes production smoothing more complicated in particular if different equipment is required for the different variants, in which case equipment change over times becomes very critical. The objective is to be able to produce the variants in any order without impacting the process time and so maintain a smooth flow of product down the production line.
The big benefit of Production Smoothing is that the production line has a takt time, this is the same as the takt time for each process that came from standardising the work. This means the maximum shift output is easily calculated (shift time / takt time) which becomes the basis for operational KPIs.
Demand Smoothing
Typically even within a week demand will vary from day-to-day, demand smoothing focusses on what can be done operationally to cope with this volume fluctuation.
In traditional manufacturing finished inventory would have been used to smooth out the demand, this is not always practical - some products cannot be stored and demand cannot be accurately forecast - plus holding inventory goes against the objective of minimising waste. Other options are;
- Extend the shifts and work overtime, this is an option if the operation is not 24 hours
- Extend the day, use time from the previous and/or next day to increase the output
- If the peak demand is predictable use annualised hours or shift patterns to increase labour when required and decrease it when it is not required
- Use temporary or agency workers
- Retain old written down equipment and use it at times of peak demand
- Short term outsourcing
With the output per hour set by Production Smoothing techniques, Demand Smoothing is a way of increasing / decreasing the output without introducing waste.
Business Modelling
A business model is a representation, typically spreadsheet based, of the operation that can be used to understand, to change, to manage and to control the operation. A good operational model allows scenarios to be reviewed a lot quicker, more cheaply, and with less risk than making changes to the physical operation. This means that it is a lot easier to understand which changes will have the biggest impact, and so where to focus effort, plus the expected outcome from any changes is better understood.
The business model can also be used as the basis for the operational KPIs. The model will give the theoretical expected result, the actual results can be bench marked against the model, and the gaps focussed on for areas of improvement.
Although not traditionally part of a lean methodology, standardised work and takt times in conjunction with volumes and operational hours make creating a model a lot simpler than an environment without standardised work.
