Gone are the days of single build assembly procedures, or at least as the sole process. While it may be beneficial to assemble some simpler builds from the ground up, high running product assembly jobs promote the use of a single piece flow line. Though MPE implemented assembly flow lines several years ago the process recently received several improvements and, more importantly, enhancements to our standard procedures.
ASSEMBLY PROCESS IMPROVEMENTS MAKE A DIFFERENCE
- Line Clearance
- Layered Process Auditing
- Inspection Checklist / Buddy Check
HOW WE’VE IMPROVED
Following the line schedule and in preparation of running a project through one of our assembly flow lines, all parts are kitted and staged in front of the flow line. Kitting the next to run items ahead of the line reduces material handling, storage, and time spent searching for parts – all of which are considered waste according to lean principles.
Component counts are documented prior to running a particular job to ensure the required quantities are present. At the end of the run, leftover parts are also counted to confirm nothing has been missed when compared to the initial count and what should have been used during assembly. The use of this procedure is called line clearance.
Utilizing sequential work stations along the assembly flow line, teammates follow detailed and station specific work instructions (WI). These work instructions are developed in order to optimize flow, minimize waste, boost productivity and provide line balance. In addition to counting total component parts needed for the total assembly run offline, at the staging part of the process, our teammates count out the respective parts needed for the station specific assembly operation.
Before product progresses from one station to the next, the operator completes an inspection checklist. Another inspection immediately follows: the operator at the next station inspects the work of the previous station and signs-off before they begin assembly at their station. We call this our buddy check. Since the inspection checklist travels with the product as it moves through the various stages of assembly we easily maintain product traceability while line efficiency can be monitored via workstation specific activity reports in order to identify pain points and/or opportunities for improvements.
Unfinished goods or partially built goods are tagged with precise details on what work station the item was last touched on, the work station the product needs to resume on, and/or a list of corrective actions to be taken. The product(s) and tag(s) are then placed in a closed off MRB (Material Review Board) area.
A Layered Process Audit ensures team members are following the standard processes set forth. The inspection of the workstation confirms that proper work instruction and revision is displayed and that the teammate is following these procedures. It also confirms that the correct parts and tools are in place, and checks that tools are calibrated and set to the correct torque. Teammates tasked with these frequent checks include assembly line quality technicians, the team leads, and assembly supervisors, including the Director of Quality. The layered process focuses on sustaining standard procedures and quality at the source: exposing issues early on in order to provide us with the opportunity to address or improve our procedures.
Unsung heroes in the changes we’ve implemented on our assembly flow lines are the ones that address productivity, ergonomics and teammate morale. We’ve improved lighting consistency and light output. Anti-fatigue mats were added to work stations to reduce worker stress. Digital displays at each work station reduces the need for paper drawings and digital calipers read and record necessary measurements automatically. The enhancements have been conducive to overall morale and quality by providing teammates with transparency of the upcoming schedule and task specific ownership. This allows individuals a voice in identifying issues, creating solutions and teammate involvement in daily meetings.
The assembly flow lines have increased our productivity and improved our quality and lead times, working specifically well for our high-running jobs and Kanban programs. Looking ahead in our improvements to the assembly flow line, our next steps may include station specific shadow boxes and retractable pneumatic hose lines.