Shop floor control begins by understanding the reason for control. Two views of running a production floor are shared with biasness towards the Material Flow View. In this article, Anand Deshpande, Founder & CEO of Admaa Consulting, and a specialist in Lean and Six Sigma consulting in the apparel industry, automotive, financial services and education sector, identifies elements required to control the output from the shop floor and concludes by offering practical tips to extract maximum production potential from the shop floor.
Shop floor is the place in the manufacturing industry where losses are accumulated or profits are made. It is the heart of any product organization, and thus should be the core competence of that organization.
Managing the shop floor has never been or ever will be an easy task. On a typical apparel shop floor, during the transformation of the raw material in the form of fabric to finished goods, i.e. apparels, we encounter issues like random disruptions, inventory pile-up, alterations, quality issues, missed shipments, heated arguments between various stakeholders and chaos.
Why is the apparel shop floor such a challenging workplace?
An apparel shop floor, in any part of the world, is characterized by two important elements – Variability and Dependency.
Variability is a change experienced over a period of time. Typically, the shop floor experiences variability in following ways:
Material: A batch of fabric rolls (shell) from the supplier could have one roll that is defective, compelling inspection of input material. Most organizations deploy a sampling plan to inspect these rolls. Inspection does not add value per se but is required to ensure a smooth production flow. It could also be that more rolls are defective and require re-ordering, thus causing delay in order execution.
Machine: It is a common sight to see a machine broken down early in the morning which requires repair or replacement after the shift commences. Random disruptions like these reduce the first hour output. Gaining momentum after sudden break in production is always a challenge.
Men/People: A new operator or a less skilled operator introduces skill variability in the system. As apparel production is very labour-intensive, speed of the slowest operator defines the speed of the production line. Assuming a less skilled operator is introduced in the collar section. He/she will reduce the production speed by at least 20 per cent.
Method: A standard method deployed in operation ensures consistency in the cycle time for each cycle, thus resulting in constant output every hour. Any deviation from the standard method impacts quality of the output as well as the time taken to produce.
Measurement: How many times have we observed two quality checkers differ on the quality characteristics of the same product? The answer is many times. Measurement variability is observed in measuring input material, semi-finished products and finished products.
Information: Variability in information about the specification of the final product between a Merchandiser and Production Executive leads to variability in the understanding of the product attributes. We hear so many times from the production floor about the style information missing from the tech pack. In such cases, the production floor makes some style changes that the customer does not really need.
On the other hand, dependency on the production floor impacts production performance in the following ways:
People Dependency: Skills in a labour-intensive industry have a deep impact on productivity, quality and production volumes. Typically, apparel industries are located in the hinterland that does not have an adequate exposure to the industrial culture. Absenteeism due to trivial reason is common. If an employee, skilled in operating the sleeve setting machine is absent, the line slows down. Moreover, if the same resource is required for two different operations, then it becomes a bottleneck.
Routing Sequence Dependency: The material flows from being raw material to a finished product with a defined routing sequence. Within cutting, the material flows from laying to cutting, then to numbering, fusing and finally bundling. The product routing sequence introduces dependency as pre-defined process steps that cannot be bypassed.
Product Changeover Dependency: During the production line changeover from one product to another, we cannot produce the new product, unless the setup required for the new product is complete.
Local Dependency: Each geographical region has its own characteristics. The political situation can always be unpredictable. Strikes, walkouts and general disruptions due to political situations are always on the cards.
Local weather, if inclement, can always cause absenteeism in large numbers, thereby affecting daily production.
The secret of production management lies in effectively combating dependency and variability. Generally speaking, the management strategies to address these variables usually deploy the ‘Resource Utilization View’ or ‘Material Flow View’.
Resource Utilization-based Production Management Strategy
The Resource Utilization View stresses the maximum utilization of resources such as Man, Machine and Material. The Plant Manager conforming to this strategy, views the plant as if it is a static unit where people and machines are occupying a fixed space on the floor. The material moves as per the laid out operation number.
This view reinforces the following elements:
• Resources are costly.
• To manage the cost of each resource, efficiency should be increased.
• To assure increased efficiency, time must not be wasted by the resource.
• To ensure that resources do not waste time, metrics that measure resource utilization must be promoted.
Utilization of the resource with no corresponding requirement in demand can only lead to waste.
The factory can also be managed by focusing on how the material flows from input process to the output process. The factory is viewed as if it is a unit engaged in transforming the material into the end-product by moving from one section to the other without any stops or interruptions.
This view reinforces the following concepts:
• Materials must flow from one process to the other without any stagnation.
• There are separate value streams for unique products, hence there are no product-intersecting flows.
• Customer demand determines resources that need to be deployed.
• The metrics to manage production are lead time, WIP to Standard WIP (SWIP) ratio, First Time Through, etc.
Making the material flow swiftly must be the ultimate goal of the plant. The production environment is shaped along this principle by ensuring that material releases on time which improves process efficiency and output quality.
Tools for smooth material flow on shop floor
To improve the material flow on the shop floor, the following initiatives can be embarked upon:
The purpose of Capacity Management is to:
• Ensure availability of capacity to meet Service Level Agreement (SLA) and quality standards.
• Balance the workload with available capacity.
• Optimize capacity continually by eliminating non-core activities.
• Establish capacity benchmark for processes (current and transitions).
• Facilitate process standardization.
To manage capacity on shop floor, usually following steps are taken:
• Mapping the process with the help of tools like Value Stream Map.
• Defining Takt Time for the process.
• Tabulating process data like cycle time, machine downtime, error rate, and cost for each step of the process.
• Adding the work content for the entire process (sum the cycle times for each element of the process).
• Calculating the exact number of people and machines required for process.
Visual Management is a practice involving the clear display of charts, lists and performance records, so that both, management and workers are continuously reminded of all the production elements that make Quality, Cost and Delivery (QCD) successful.
The purpose of Visual Management is to:
• Make problems visible, i.e. detecting abnormalities so that employees can take corrective action.
• Stay in touch with reality as Visual Management is a method for determining whether everything is under control or not, and for sending a warning the moment an abnormality arises.
• Setting targets for improvement.
To manage the shop floor visually, following steps can be taken:
• Embark upon workplace organization by deploying 5S initiative.
• Build standards for workplace by creating markings on the floor and visual dashboards.
• Warn about abnormalities by deploying visual indicators, buzzers, andon lights and visual displays.
• Stop and prevent abnormalities by deploying error detection and error prevention strategies.
Skill Management is about the provisioning of skills for effective and efficient service delivery for a desired quality standard. Skill building relies on effective anticipation of skill requirement, knowledge of skill gaps and continuous up-skilling.
The purpose of Skill Management is to:
• Develop skills continually to deliver best value to the customer.
• Identify current skill deficit and anticipate future skill needs.
• Train and develop team members on current skill deficit.
Skills on the shop floor can be managed in following ways:
• Prepare the skill matrix to identify skill deficit in the process/department.
• Address skill gaps by creating a ‘Training Needs Analysis’ document and customize training (create training calendar) to enhance skills.
• Monitor training of the individual.
• Review and update skill matrix at a defined frequency.
Performance Management is a practice that measures organizational performance, identifies the root cause of variation in performance and addresses the gaps through Continuous Improvement.
The purpose of Performance Management is to:
• Design Specific, Measurable, Attainable, Relevant, and Trackable (SMART) metrics to align objectives across all levels of the organization.
• Review metrics and identify gaps.
• Design corrective action plans to plug the gaps and improve performance.
• Drive improvements by taking up continuous improvement projects.
We could manage the performance on the shop floor in the following ways:
• Review performance measures at a defined frequency.
• Conduct a gap analysis on performance.
• Implement corrective measures to plug the gaps.
• Plan-Do-Check-Act (PDCA) analysis on implemented measures.
The purpose of Daily Accountability is to:
• Reinforce Lean Management’s focus on processes.
• Through meetings identify opportunities for improvement.
• Ensure follow-up on task assignments made in response to yesterday’s problems.
We reinforce daily accountability on the shop floor by conducting problem-solving meetings between:
• Team leader and production crew.
• Supervisors and team leaders.
• Value stream leader with supervisor and support group.
• Value stream leader with production manager and support group.
Generally, these meetings are focused on discussing the below agendas:
• Assignments and special items for the day.
• Daily rotation and labour plans for the day.
• On designated days topics like 5S, Safety, Quality, Delivery, Cost, Morale and Environment (SQDCME) boards may receive special focus.
• Daily performance data added to trend charts on Safety, Quality, Delivery and Cost – along with any other important parameter.
Quality Management ensures the best quality product to the client against a defined standard at the lowest cost.
The purpose of Quality Management is to:
• Focus on quality at source.
• Rely less on inspections and more on defect detection and defect prevention.
• Error proofing a process step wherever possible, and eliminating opportunity for an error.
• Process Confirmation and Process Standardization to ensure consistent quality.
• Problem solving through Root Cause Analysis.
To manage quality following sequence of measures can be taken:
• Identify Critical to Satisfaction (CTS) characteristics from the voice of the customer.
• Filter the Critical to Quality (CTQ) characteristics from the CTS.
• Define a quality metric for the CTQs.
• Conduct a gap analysis on expected performance versus the actual.
• Conduct a Root Cause Analysis to know reasons for customer dissatisfaction.
• Decide corrective and preventive actions for each root cause.
• Review quality metrics over a defined period of time.
Changeover Management ensures that time to successfully switchover from earlier product to next product is continually reduced.
The purpose of Changeover Management is to:
• Reduce all non-value activities during the changover process.
• Set up all the machines to produce the next product.
• Giving a heads-up to the operators and making them ready to produce the next product.
• Reduce the changover time as organization matures.
To manage changeovers we could do the following:
• Identify all the activites required for a changeover.
• Segregate activities into internal work (that requires machine to be stopped) and external work.
• Try to convert as much internal work into external work.
• Keep reducing time required to perform internal work.
WIP Control ensures that WIP in the system at specific points is maintained to consistently achieve the bottleneck rate under current process cycle times.
The purpose of WIP Control is to restore buffers, keep buffers. It also facilitates the consistency of output through the bottleneck by not starving it.
To Manage WIP, the following strategies can be adopted:
• Maintaining SWIP at critical points along the production system.
• Not starving or blocking the bottleneck by keeping WIP before the bottleneck and space to offload output from the bottleneck to not block the bottleneck.
• Create a metric of WIP to SWIP ratio where SWIP is Standard WIP that is supposed to be maintained.
If the WIP to SWIP Ratio is greater than 1.2, the WIP is likely to go out of control. If it is less than 0.8, the WIP is not enough.
Practical tips to manage material flow on apparel shop floor
Let us assume that a jacket production line produces jackets at the rate of 480 pieces per day. As shown in Illustration B, the cutting section produces in batches while the sewing and finishing use single-piece flow system. The sewing process is divided into Parts Assembly and Final Assembly. The Parts Assembly produces collar, lining, front and back, and sleeve concurrently. In the Final Assembly, these parts are sewn together.
To enhance productivity, quality and production, following pointers should be focused upon:
Create a metric of WIP to SWIP ratio where SWIP is Standard WIP that is supposed to be maintained. If the WIP to SWIP ratio is greater than 1.2, the WIP is likely to go out of control. If it is less than 0.8, the WIP is not enough.
Balance the line with respect to Takt Time:
The Takt Time based on customer demand of 480 per day is 60 seconds. Balance the line in such a way that each operator works to a cycle time of at least 50 seconds, if not less. Any operator who works with a cycle time of below 50 seconds, then he/she would tend to overproduce. Lower cycle times, considerably lower than the Takt Time, tend to hide quality issues, niggling machine problems, etc. By loading the operator with work cycle time that is closer to Takt Time, we also expose waste in the production system.
Parts section should be ahead of the assembly at all times
The Supermarkets between parts sewing and final sewing assembly should maintain Standard WIP of at least 2 hours to enable assembly to be run at all times. In a situation where the parts section runs significantly ahead of the assembly, stop the line and multi-skill employees. Another way of utilizing excess resources is to clear the alterations in the line.
If the final assembly is running faster than the parts assembly line, slow down the assembly section to match the parts assembly line’s speed. The excess resources generated could be deployed to clear the rework and speed-up the parts assembly line.
Synchronize the production of parts by matching serial numbers
As the concurrent output from parts sewing arrives at the pairing station before final assembly, invariably we discover a mismatch in serial numbers between various parts. Serial No. 111 for collar may arrive first as opposed to Serial No. 113 of front and back.
Ensure that the same serial numbers are produced concurrently to avoid mismatch of parts. One could use a strike-off sheet of serial numbers. The end line QC can strike off all the serial numbers that have been passed for every part. The serial numbers that have not been struck-off are the ones that need to be tracked on the line and expedited.
Avoid first hour production losses
The first hour output almost always sets the pace for the day. If the first hour output is at least 80 per cent of desired output per hour, there is every chance of meeting the daily target. Therefore, to avoid first hour production losses, following steps should be taken:
• Man the production line within 10 minutes of the start of the shift.
• Consider unplanned absenteeism and plan for it on the previous day with due diligence with the team leaders.
• Do not empty the last leg of assembly line on the previous day (the reason being that if the line is pulled through to improve production on previous day, there is a huge gap in morning that reduces first hour output to under 30 per cent of target).
• Maintenance personnel must be present in the line at the start of shift to immediately respond to breakdowns.
• The supervisor must observe critical to quality processes by confirming the process in the very first hour.
Keep production floor neat and clean at all times
They say that a shop floor is a reflection of the management. Workplace organization is the first element of production management that must get the utmost priority. To organize the workplace, ensure the following:
• Devise hourly cleaning schedules across production lines.
• Ensure that teams keep workplace neat and clean before leaving for home.
• Embark upon a 5S journey and do not stop.
• Put 5S posters all over the jacket line to encourage cleanliness.
• Define Standard WIP across all sections of the production system and maintain the WIP.
Devise an escalation policy
Escalation policy is a document that sets the guidelines for an issue to be escalated to the Plant Manager if its resolution does not happen in a certain time frame. The escalation policy creates a ‘Sense of Urgency’ on the production floor. For instance, the supervisor must escalate a machine breakdown to the plant manager if it is not resolved in 20 minutes.
Escalation policy sets the guidelines for an issue to be escalated to the Plant Manager if its resolution does not happen in a certain time frame. The escalation policy creates a ‘Sense of Urgency’ on the production floor.
Generate daily production reports for all sections
Production reports are a reflection of the floor performance and so should they be. It is often observed that most plants are run with macro-level production reports devoid of any details about reasons for the production losses. The recommendation is to create production reports that highlight the following:
• Reasons for the day’s losses (absenteeism, machine breakdown, etc.)
• Report production losses on an hourly basis.
• Supervisors must update production reports on an hourly basis.
• Production reports must reach the plant manager within 15 minutes of end of shift.
• Analyse reports to detect trends and areas for improvement on a monthly basis (let the respective supervisors do it for you).
• Embark on improving data analytics.
Review production on an hourly basis
Most production plants conduct a sunrise or sunset meeting, which does not add much value. Instead conducting meetings on the floor on an hourly basis will yield better results. Hourly meetings help detect abnormalities and encourage a problem-solving culture. If there are no hourly meetings, vague reasons are put forth for production losses and we are clueless about the production rhythm for the day.
Recommendations on the process of conducting hourly meetings:
• Create a visual centre displaying hourly production and top 10 issues in delivery and quality. The floor is expected to assemble at this centre every hour to discuss hourly production issues.
• Enforce the discipline of hourly reviews across all the departments.
• Identify bottleneck areas during hourly review and focus all your resources to bring the bottleneck areas up to speed with rest of the line.
• Seek agreement on next steps from supervisors during the review.
• Validate the production target per hour with the budgeted target per hour.
• Enforce the reporting of hourly production on an A3 paper than using the whiteboards. Paper is ideal recording mechanism for future reference and validation.
Encourage a problem-solving culture by using 8D methodology to solve quality problems
8D is a problem solving methodology deployed to address quality issues faced by automotive factories as reported from the field. It is a structured approach that involves the following activities:
• Defining the problem.
• Identifying the interim containment action to tide over the crisis.
• Determining the root cause.
• Deciding the permanent corrective action.
• Ensuring that the problem does recur.
The 8D approach could be used not only for problems that are reported by external customers, but also by problems or internal defects reported by internal customers. A problem like ‘loop slant’ or ‘lapel shape-out’ could easily be resolved using this structured approach.
Multi-skill employees on a daily basis
In a labour-intensive industry such as the apparel industry, multi-skilling must become a day-to-day production priority. It is observed that absenteeism is very high on the floor leading to skill deficit. This in turn puts the brakes on a smooth production flow.
There are two engagement areas for upskilling – Classroom Training and On-the-job Training. The employee on boarding must begin with skill development and due time must be allowed for the same. We observe that to develop some proficiency in sewing at least 2-3 weeks are required. It makes sense to have a bench in place that is ready to be tapped at any time.
On-the-job training requires the employee to be skilled specifically for certain product styles. This also involve training the employee on at least four skills that are critical to the success of the output rate. Not only does it improve operator’s speed, but also helps counter unplanned absenteeism.
A technique the apparel industry can borrow from the automotive industry is to rotate the employee on four jobs in a day, i.e. two hours on every job. In this way, within a month or so, the operator would get trained on four skills.
A tool known as the ‘Skill Matrix’ can be used to identify the existing skill gaps, draw up training plans and follow-up on upskilling progress. A monthly review of the skill matrix is necessary to continue the skill development cycle.