What is Lean Manufacturing/Lean Production?[Back to FAQ's] Lean techniques are, in their most basic form, the systematic identification and elimination of waste (80%), and the implementation of the concepts of continuous flow and customer pull. The touted benefits of lean production systems are 50% lower production costs, 50% less personnel, 50% less time to field new products, higher quality, higher profitability, higher system flexibility, and more... However, by continually focusing on waste reduction, there are truly no end to the benefits that can be achieved.

Generally, 5 areas drive lean manufacturing/production: cost, quality, delivery, safety, and morale. Just as mass production is recognized as the production system of the 20th century, lean production is viewed as the production system of the 21st century.

What is the Lean Enterprise?[Back to FAQ's] The 'Lean Enterprise' encompasses the entire production system, beginning with the customer, and includes the product sales outlet, the final assembler, product design, and all tiers of the supply chain (to include raw material mining and processing). Any truly 'lean' system is highly dependent on the demands of its customers and the reliability of its suppliers. No implementation of lean manufacturing can reach its full potential without including the entire 'enterprise' in its planning.What are the elements of Lean Manufacturing?[Back to FAQ's] The basic elements of are waste elimination, continuous one-piece workflow, and customer pull. When these elements are focused in the areas of cost, quality, and delivery, this forms the basis for an effective lean production system. Why are Japanese terms typically used in defining lean principles?[Back to

FAQ's] Typically, these terms are used (and misused) in order to convey broad concepts with iconic (representative) terminology. Once properly explained, the term KANBAN can be more descriptive than THOSE LITTLE CARDS WHICH HELP US CONTROL PRODUCT MOVES. However, use of these terms can have a negative effect, especially if the culture of a particular organization is predisposed against all things non-American. Choose carefully the training methods (and terms) you use when conveying lean tools and methods, and you will have a much easier time during your lean implementation.

For a list of 'lean definitions', click here.

If less personnel are required in a 'lean facility', what is done with 'surplus personnel'? This is best illustrated in the Lean Personnel Model. Are 'lean' techniques applicable in a service-oriented industry or office environment?[Back to FAQ's] Every 'system' contains waste. Whether you are producing a product, processing a material, or providing a service, there are elements which are considered 'waste' (or, said another way, something that does not provide value to your customer). The techniques for analyzing systems, identifying and reducing waste, and focusing on the customer are applicable in any system, and in any industry. Some of the industries and sectors discussed on NWLEAN include:

Manufacturing Production

(discreet, continuous) Assembly Maintenance

(including repair, re-manufacturing) Services Government application

Various other industry segments (see toolbar at top of page)

Are there any published standards for implementing lean techniques?[Back

to FAQ's] The Society of Automotive Engineers has published standards SAE J4000 (Identification and Measurement of Best Practice in Implementation of Lean Operation) and SAE J4001 (Implementation of Lean Operation User Manual). These standards are structured like a '5S' type implementation, and are 'high level concept, low level detail' documents.

Any implementation of lean techniques will necessarily be fundamentally different, depending on various factors (such as industry, internal culture, internal business considerations). The tools used to implement lean operations, and the order in which you apply/combine them, are highly dependent on whether you are primarily a discrete manufacturer, continuous producer, or provider of a service.

The SAE standards provide a very good skeleton or framework, but it remains incumbent upon each organization to identify the correct mix of tools and techniques which will provide the 'meat', or bottom line relevance, to the lean implementation.

Here are some of the common terms found in Lean Manufacturing. If you would like to comment or make additions to this list, contact the LEANMASTER... [Back to Top]

[A thru F] [G thru L] [M thru S] [T thru Z]andon - a system of flashing lights used to indicate production status in one or more work centers; the number of lights and their possible colors can vary, even by work center within a plant; however, the traditional colors and their meanings are: green - no problems yellow - situation requires attention red - production stopped; attention urgently neededautonomation - in Toyota parlance, automation with a human touch; English translation of jidoka (see below).

bakayoke - literally, 'fool-proofing', this term quickly fell into disuse as it was perceived by workers as being applicable to 'fools' (baka). A more descriptive term is poke-yoke (see below).

cellular manufacturing - an approach in which manufacturing work centers [cells] have the total capabilities needed to produce an item or group of similar items; contrasts to setting up work centers on the basis of similar equipment or capabilities, in which case items must move among multiple work centers before they are completed; the term group technology is sometimes used to distinguish cells that produce a relatively large family [group] of similar items.

cycle time - the normal time to complete an operation on a product. This in NOT the same as takt time (see below), which is the rate at which customers are demanding a product.

error-proofing - a manufacturing technique of preventing production errors by designing the manufacturing process, equipment, and tools so that an operation literally cannot be performed incorrectly (see poke-yoke).

ERP - Enterprise Resource Planning. The techniques of MRPII (see below) adapted to all areas of an organization, as opposed to just within manufacturing/production.

Usually implemented as a comprehensive (and therefore expensive) software solution, used to manage all aspects of a business.

5S - refers to the five words seiri, seiton, seison, seiketsu, shitsuke (see below for definitions). These words are shorthand expressions for principles of maintaining an effective, efficient workplace. 5S refers to a structured program of using these principles as the basis for continuous improvement in the workplace.

5 Why's - a simple technique, used to reveal the 'root cause' (as opposed to symptoms) of a problem. The technique asks 'why' the symptom occurred, 'why' the situation which allowed the symptom exists, and so on, until the root cause is finally discovered. Eliminating the root cause prevents the symptom from ever occurring again. If it does occur, the root cause was not properly addressed.

HINT - if your '5 Why' exercise seems to be pointing to 'operator error' as the root cause, you are going down the wrong path. Operators only do what our production systems allow them to do, so the root cause is in our systems, not our workers.

flexible manufacturing system - an integrated manufacturing capability to produce small numbers of a great variety of items at low unit cost; an FMS is also characterized by low changeover time and rapid response time.

[Back to Definitions]

gemba - The shop floor, workplace, or work site.

heijunka - A production scheduling/leveling tool, essentially to distribute kanban cards in an efficient manner.

hosin planning - Policy management or Strategy deployment. A method for establishing goals (and policy which supports and enhances those goals) and ensuring that these goals are the primary focus of the organization.

jidoka - a Japanese word which translates as autonomation; a form of automation in which machinery automatically inspects each item after producing it, ceasing production and notifying humans if a defect is detected; Toyota expands the meaning of jidoka to include the responsibility of all workers to function similarly, i.e. to check every item produced and to make no more if a defect is detected, until the cause of the defect has been identified and corrected.

jishu kanri - self-management, or voluntary participation.

just-in-time - a production scheduling concept that calls for any item needed at a production operation - whether raw material, finished item, or anything in between, to be produced and available precisely when needed, neither a moment earlier nor later.

jutsu - to talk, or ‘the art of’ (i.e., 'leanjutsu: the art of lean production').

kaikaku - A rapid and radical change process, sometimes used as a precursor to kaizen activities.

kaizen - the philosophy of continual improvement, that every process can and should be continually evaluated and improved in terms of time required, resources used, resultant quality, and other aspects relevant to the process.

kanban - a card or sheet used to authorize production or movement of an item; when fully implemented, kanban (the plural is the same as the singular) operates according to the following rules:

1. All production and movement of parts and material take place only as required by a downstream operation, i.e. all manufacturing and procurement are ultimately driven by the requirements of final assembly or the equivalent.

2. The specific tool which authorizes production or movement is called a kanban. The word literally means card or sign, but it can legitimately refer to a container or other authorizing device. Kanban have various formats and content as appropriate for their usage; for example, a kanban for a vendor is different than a kanban for an internal machining operation.

3. The quantity authorized per individual kanban is minimal, ideally one. The number of circulating or available kanban for an item is determined by the demand rate for the item and the time required to produce or acquire more. This number generally is established and remains unchanged unless demand or other circumstances are altered dramatically; in this way inventory is kept under control while production is forced to keep pace with shipment volume. A routine exception to this rule is that managers and workers are continually exhorted to improve their processes and thereby reduce the number of kanban required.

karoshi - death from overwork.

lean enterprise - all aspects of an organization, from the beginning of the supply chain, thru the production process, and including your customer base. As you 'lean' your organization, you will find that certain contraints exist outside of your company. These constraints must be dealt with in order to further improve operations, so the supply chain, regulatory authorities, and even your customers must be involved in your lean efforts.

lean manufacturing or lean production - the philosophy of continually reducing waste in all areas and in all forms; an English phrase coined to summarize Japanese manufacturing techniques (specifically, the Toyota Production System).

line balancing - equalizing cycle times [productive capacity, assuming 100% capacity utilization] for relatively small units of the manufacturing process, through proper assignment of workers and machines; ensures smooth production flow.

[Back to Definitions]

mistake-proofing - a manufacturing technique of providing a signal when an error is about to be introduced into the production process. Many times, this is in the form of a checklist.

mixed-model production - capability to produce a variety of models, that in fact differ in labor and material content, on the same production line; allows for efficient utilization of resources while providing rapid response to marketplace demands.

mizusumashi - the classic 'water spider', who performs a wide range of tasks which allow workers to perform 'value-added' tasks.

mokeru - the Japanese term for the industrial engineering, more properly translated as ‘profit-making I.E.’.

muda (waste) - activities and results to be eliminated. There are 7 categories of waste:

1. Excess production and early production 2. Delays 3. Movement and transport 4. Poor process design 5. Inventory 6. Inefficient performance of a process 7. Making defective items

mura - inconsistency or variation

muri - unreasonableness

MRP/MRPII - Material Requirements Planning. A technique (usually augmented with software) for planning for production material requirements, based on historic usage, historic production and delivery lead times, and EOQ costing. MRPII software programs have the added capability for capacity planning, scheduling, and shop floor control. The scheduling and shop floor components of MRPII are highly unreliable (unless perfect forecasts are available, which never are) and tend to introduce huge overhead costs in terms of inventory and production lead times.

nagara - smooth production flow, ideally one piece at a time, characterized by synchronization [balancing] of production processes and maximum utilization of available time, including overlapping of operations where practical.

ninjutsu - the art of invisibility (applies to management).

non-value-added - those actions in the workplace that the customer is not willing to pay for. (See value below)

one-piece flow - the concept of reducing production batch/lot sizes to minimal size, preferable to a single unit. This can have dramatic affects on raw material, WIP, and finished goods inventories, as well as on production lead times, quality, and costs.

Pareto chart - a tool (histogram or vertical bar chart) used for analyzing the relative occurrence of defects, developed by Italian economist Vilfredo Pareto, circa A.D. 1900. Pareto's Law refers to Pareto's observation that wealth distribution generally follows a pattern where 20% of people control 80% of all wealth. This principle has been generalized to show that, in general, 20% of categories contain 80% of the data, and hence is also known as the 80/20 rule.

poka-yoke - 'mistake-proofing', a means of providing a visual or other signal to indicate a characteristic state. Often referred to as 'error-proofing', poke-yoke is actually the first step in truly error-proofing a system. Error-proofing is a manufacturing technique of preventing errors by designing the manufacturing process, equipment, and tools so that an operation literally cannot be performed incorrectly.

pull system - a manufacturing planning system based on communication of actual real-time needs from downstream operations (ultimately final assembly or the equivalent). Contrast with PUSH systems, which schedule operations according to theoretical downstream result, based on a 'best-guess' planning, MRP, or equivalent.

seiri - or SORT; eliminating everything not required for the work being performed. The first 'S' (see 5S, above.)

seiton - or STANDARDIZE; efficient placement and arrangement of equipment and material. The second 'S' (see 5S, above.)

seison - or SANITIZE; maintain tidiness and cleanliness in the workplace. The third 'S' (see 5S, above)

seiketsu - or SUSTAIN; ongoing, standardized, continually improving seiri, seiton, seison. The fourth 'S' (see 5S, above.)

shitsuke - discipline with leadership. The fifth 'S' (see 5S, above.)

seiban - Seiban is the name of a Japanese management practice taken from the Japanese words "sei", which means manufacturing, and "ban", which means number. A Seiban number is assigned to all parts, materials, and purchase orders associated with a particular customer job, or with a project, or anything else. This enables a manufacturer to track everything related with a particular product, project, or customer. It also facilitates setting aside inventory for specific projects or priorities. That makes it great for project and build-to-order manufacturing.

sensei - one who provides information; a teacher, instructor, or rabbi.

setup time - work required to change over a machine or process from one item or operation to the next item or operation; can be divided into two types:

1. internal: setup work that can be done only when the machine or process is not actively engaged in production; OR

2. external: setup work that can be done concurrently with the machine or process performing production duties.

saki - a rice wine, preferably served warmed.

shojinka - continually optimizing the number of workers in a work center to meet the type and volume of demand imposed on the work center; shojinka requires workers trained in multiple disciplines; work center layout, such as U-shaped or circular, that supports a variable number of workers performing the tasks in the layout; the capability to vary the manufacturing process as appropriate to fit the demand profile.

SMED - abbreviation for Single Minute Exchange of Die; literally, changing a die on a forming or stamping machine in a minute or less; broadly, the ability to perform any setup activity in a minute or less of machine or process downtime; the key to doing this is frequently the capability to convert internal setup time to external setup time; variations on SMED include:

1. Single-digit setup: performing a setup activity in a single-digit number of minutes, i.e. fewer than ten.

2. OTED: One touch exchange of die; literally, changing a die with one physical motion such as pushing a button; broadly, an extremely simple procedure for performing a setup activity.

soikufu - creative thinking or inventive ideas. As part of a comprehensive teian system, allowing and encouraging soikufu ensures personal participation and contribution in the continuous improvement process.

sushi - a seaweed wrap, containing rice and other ingredients (most notably but not exclusively, raw fish), particularly good for your health and heart, and available in wide variety.

[Back to Definitions]

takt time - takt, is a German term for rhythm. Takt time is the rate at which customers are demanding a product. This is NOT the same as cycle time, which is the normal time to complete an operation on a product (which should be less than or equal to takt time).

teian - a proposal, proposition, or suggestion. A teian system is a system which encourages and allows workers to actively propose and implement no-cost and low-cost process improvements. (See SOIKUFU.)

Toyota - modification of Toyoda, meaning abundant rice field, by the Toyota marketing department. Toyoda is the family name of the founders of the Toyota Motor Company.

value - From the perspective of the customer, those aspects or features of our products they are willing to pay for.

value-added - Those production steps that transform raw materials directly into the features for which the customer assigns value.

water spider - one who performs a wide range of tasks which allow workers to perform 'value-added' tasks.

WIP - Work-in-Process inventory, or inventory that exists (in batches) between workstations.

WCM - world class manufacturing is the philosophy of being the best, the fastest, and the lowest cost producer of a product or service. It implies the constant improvement of products , processes, and services to remain an industry leader and provide the best choice for customers, regardless of where they are in the process.

KAIZEN TEMPLATE

By Jon Miller | Post Date: February 4, 2008 11:41 PM | Comments: 12

A reader pointed out that the takt time for posting the 101 kaizen template has exceeded. It is true that we have not been hitting a consistent 1 template per 3.5 days. To meet our goal for 101 of these by the end of 2008 we will need to recalculate our takt time. Conveniently, we have a takt time calculator as a template for this.

There are two sections to this kaizen template in order to make it easy to show two possible takt time scenarios. There may be an average takt time and a takt time during peak volumes. This information is useful in designing production lines or equipment so that the maximum capacity as well as the daily average can be taken into consideration.

The two sheets in the graphic above are used to illustrate that there are two different shift structures with different numbers of working hours and thus different takt times on these days. For example if there was an "A" shift working four 10-hour days and a "B" shift working three 12-hour days for a 7-day operation the takt could be matched by adjusting average demand.

This takt time calculator will calculate takt time for you under a variety of conditions such as break times, number of working shifts, shift structures and working hours per shift. Fill in the white cells. The blue cells will calculate automatically. The sheet is protected so that you don't accidentally delete the formulas. It is not password protected so feel free to select Tool / Protection / Unprotect Sheet if you would like to modify this

template.

Back to the issue of non-performance to takt time on this blog. What is the kaizen action to be taken? Of course root cause analysis and corrective action must follow, but an immediate recovery plan is necessary in the mean time. For illustrative purposes the takt time calculator was modified to show the original plan of one kaizen template every 3.5 days, not adjusted to one every 2.1 days based on the remaining number of kaizen templates (95) the remaining number of blogging months (11) in 2008 and a more realistic number of "available days" per month for blogging (20).

A kaizen template every two blogging days may get to be boring, but a promise is a promise so the challenge will be to meet this goal while keeping it fresh and interesting.

ShareThis

Dear JonThanks for another great template, but I think you can reduce the demand over the remaining 11 months of this year by the 6 templates you already posted. Therefore your calculation of Takt increases from 2.18 to 2.32 days best of luckRegardsChris

Poster: Chris Nicholls | Post Date: February 6, 2008 7:33 AM

Oops. Thanks Chris. You are right. 95 left to go, not 101.

Poster: Jon Miller | Post Date: February 6, 2008 9:53 AM

Hi Jon this is a really useful and great template, it's going to be really useful to me, i just have one question/slash observation, Planned downtime cells (C10 and C25) are not referenced in any other cell, so either is information we are not going to need/use (waste) or it should be referenced to Net Working time cells (C11 and C26) please clear this out for me.

thanks.

Poster: Alberto Cárdenas | Post Date: February 17, 2008 3:40 PM

Thanks for the observation Alberto. The template has been corrected and uploaded again. The C10 and C25 cells are indeed relevant now they are referenced as part of the calculation correctly.

That should be a good reminder to everyone to check your their work for errors after modifying this template and before distributing it.

Poster: Jon Miller | Post Date: February 17, 2008 8:21 PM

I have question, I know how to calculate tt, my problem is a I have a production line that has 3 product families produced. Product 1 volume 356/day sum of cycles 80 sec, Product 2 volume is 103/day sum of cycles 200 sec and Product 3 volume is 89/day sum of cycles 152. How do I give each product family a TT.? Staffing is 3, 25800 sec. Available Time

Poster: huntr@hearthnhome.com | Post Date: June 12, 2008 12:30 PM

If you have 3 product families you need to calculate 3 takt times. Staffing is irrelevant. I wouldn't recommend running a mixed model line unless the downstream customer needs one of each product to make a set or shipment. It is better to run one product family for a few hours until the daily demand is met, then switch to another, etc. in a daily pattern. Roughly speaking you will need 2,8480 sec (80 x 356) for Product 1, 20,600 sec (103 x 200) for Product 2 and 13,528 (89 x 152) for Product 3. The sum of cycle time (I am assuming you mean manual time) is 62,608 sec so the optimum staffing is 2.4 people.

If you have one piece flow and cross trained workers it becomes much easier since you can simply divide the work content for each product by 2 or 3 evenly and run until finished based on not the "true" takt but something called "actual takt". For example if you could balance the workload and pace the flow for Product 2 at 67 seconds per person with 3 workers you could finish your daily requirement in about 3 hours and 20 min.

Good luck!

Poster: Jon Miller | Post Date: June 13, 2008 10:05 AM

Thanks

This website really help me doing report.

Poster: wan | Post Date: February 6, 2009 5:11 AM

This is a good calculator. But it assumes that the customer demand has the same work time per piece, do you have a calculator for mixed model cells?

Poster: Ron Benedict | Post Date: April 6, 2009 11:14 AM

Hi Ron

You can use the same calculator.

If you are running lots of different models AAABBBCCC then determine the capacity needed (minutes) to run that lot, set that as the available time, and calculate the model-specific takt.

If you are running ABCABCABC then it it's a question of how balanced the cycle times are between A, B and C. The calculation of net available time divided by demand does not change because the cycle time or mix changes, unless the cycle time difference is greater than 10%.

In that case you will want to use a weighting to determine the 1-piece equivalent for the longer cycle time (not lead time but processing time) items. For example if product A was 5 minutes, B was 7.5 minutes and C was 10 minutes processing time then demand weighting for item A = 1, item B = 1.5 and C = 2. If your demand was 30 pieces of A, 30 pieces of B and 30 pieces of C, you would want to calculate demand based on 30, 45 and 60 or 135 pieces equivalent.

It's much easier to do it in lots AAABBBCCC so unless the cycle times are stable and nearly identical, I would go that way. Feel free to add more detail and I'll try to explain more precisely to your situation.

Poster: Jon Miller | Post Date: April 12, 2009 6:30 PM

Its a followup question from the previous comment. Our production facility lines have seven lines and each one of them supports more than 50 products. Each one of them has its own rate of production based on the process constraint.Both work content and demand changes for all these products. Is there any way we can have a common TAKT or a rate for each one of those models. How do we determine the correct TAKT for all these 100 models.

Thanks,

Poster: JP | Post Date: October 6, 2009 12:51 PM

Hi JP

I am not sure having a common takt is desirable in your case. Unless the models that run on each line fit into product families with similar process flows and work content, pacing the work to takt time on a high mix line will be difficult. It's a bit hard to give you a good answer while discussing an abstract scenario. If you would e-mail me some more details perhaps I can give a more precise answer.

Poster: Jon Miller | Post Date: October 6, 2009 4:34 PM

I have just moved from a role where the takt was 55 seconds into a new role where the customer requirement is one part every day. Does anyone have experience running to this kind of timescale.

Poster: Steve Coath | Post Date: August 14, 2010 12:15 PM

Read more: Lean Manufacturing Blog, Kaizen Articles and Advice | Gemba Panta Rei

Takt Time. Satisfacer la demanda que tiene el cliente sobre un determinado producto o servicio es lo que permite la existencia y permanencia de una empresa. Por ello, para seguir existiendo, es vital entender la demanda del cliente, incluyendo las características de calidad, tiempos de entrega (Lead Time) y precio. El cliente es quien marca el ritmo, decide la manera y forma en la que se le entregaran los productos o servicios que desea; además es quien decide que agrega y que no agrega valor dentro de los procesos, que es lo que genera desperdicio y por lo cual no esta dispuesto a pagar. Por lo tanto, de la información que se tenga de la demanda del cliente, se debe determinar el takt time, o el ritmo de producción que marca el cliente. “TAKT” es una palabra en alemán que significa “ritmo”. Entonces, esto quiere decir que el takt time marca el ritmo de lo que el cliente esta demandando, al cual la compañía requiere producir su producto con el fin de satisfacerlo. Producir con el takt time significa que los ritmos de producción y de ventas están sincronizados, que es una de las metas de Lean Manufacturing. Como se calcula el Takt Time. El Takt time se calcula dividiendo el tiempo de producción disponible (o el tiempo disponible de trabajo por turno) entre la cantidad total requerida (o la demanda del cliente por turno). Se calcula en unidades de tiempo, siendo los segundos los más utilizados. Takt Time =    Tiempo de producción disponible        o    Tiempo de trabajo por turno                              Cantidad total requerida                         Demanda del cliente por turno Takt Time =      Tiempo                           Volumen Ejemplo.- Suponiendo que un proceso de manufactura tenga 9.6 hrs. Disponibles en el día. De ese tiempo se tienen que eliminar el tiempo en que, normalmente, se detiene el proceso

Herramientas y Técnicas  Lean Manufacturing en sistemas de producción y calidad.  Universidad Autónoma del Estado de Hidalgo. Autor: Guillermo Maldonado Villalva. Ingeniería Industrial.   - 5 (desayunos, comidas, descansos, etc.); entonces, se tiene que el tiempo de producción disponible es:                    Tiempo de producción disponible:    9.6 hrs. x  60 min. =   576 min.                                                                               Descanso 10 min.  =                  -10 min.                                                                           2 comidas 15min. c/u =                 -  30min.                                                                                  Junta de 10 min.  =                  -10 min.                                                                                     Tiempo perdido =                 - 50min.                                   576 min. – 50 min. = 526 min.                                                                    526 min. x  60 segundos =    31, 560 seg.                                                                                                                   Para este proceso, el cliente esta demandando 2,000 unidades por día (cantidad total requerida), por lo tanto el Takt Time se calcula:                               Takt Time =       Tiempo de prod. disponible            31, 560 seg.                                                            Cantidad total requerida             2, 000 unidades                               Takt Time =  15.78 seg.  por unidad. Esto quiere decir que el cliente esta comprando este producto a un ritmo de una unidad cada 15.78 seg. Este es el ritmo que se puede manejar para este producto y sus componentes para alcanzar la meta. Puntos clave a tomar en cuenta para el Takt Time. Proveer rápida respuesta (dentro del taka time) a los problemas que se presenten en las áreas de producción y de apoyo. Eliminar las causas de los tiempos caídos o fallas no programadas. El takt time es un rango de tiempo o ritmo en el cual una compañía debe producir sus productos para satisfacer la demanda del cliente. El takt time mantiene un paso regular y predecible que forma parte del trabajo estandarizado. De ser calculado antes de que las actividades puedan ser planeadas. Cada vez que el takt time cambie, las actividades del personal deben cambiar, así como muy probablemente el layout de las células de trabajo. En caso de que el volumen aumente o disminuya, el takt time debe ser ajustado para que la demanda y la producción estén sincronizadas. Si la demanda disminuye, el takt time aumenta, y si la demanda aumenta, el takt time disminuye

Takt Time: producción vs optimización

Los empresarios de la industria manufacturera enfrentan la necesidad de armonizar la producción con la demanda de los clientes. Un desafío que a menudo implica cambiar la estrategia de gestión, lo que no es fácil de hacer en tiempos de incertidumbre. En este marco nos puede dar una mano el cálculo del Takt Time, de Toyota.

Definitivamente es momento de entender que producir más productos más rápido, no es siempre lo mejor.

Los “nuevos industriales” suelen poner más atención al uso de las materias primas, semielaborados y productos terminados, los recursos humanos, la capacidad de los equipos combinando estos factores con los pedidos del cliente.

Ya sabemos… es fácil decirlo pero difícil hacerlo… ¡! Encima en Argentina tenemos los problemas de las crisis y las variaciones abruptas de demanda, dificultades en la cadena de abastecimiento, y clientes ‘volátiles’… Para manejar estos procesos de sincronización entre la capacidad productiva y la demanda y establecer niveles seguros de existencias, los dirigentes industriales suelen contar con formulas y tecnología informática para tomar las decisiones adecuadas en el tiempo adecuado.

Pero los expertos aseguran que en realidad la métrica de este proceso es muy simple. Identificar y comprender estos elementos básicos comunes de éxito es un paso crucial para optimizar la capacidad y la rentabilidad.

De allí que en Toyota se haya optado por definir la velocidad de producción calculando el Takt Time , o sea ‘el tiempo de producción disponible dividido la proporción de la demanda del cliente’.

Takt-Time= (Tiempo total disponible/día)                 -------------------------------------                      (Pedidos del cliente/día)

Si los clientes exigen 200 productos al día y la fabrica trabaja durante 400 minutos por día, el tiempo takt es de dos minutos. Esta variable mide  el ritmo de la demanda que debe ser empardado por las actividades operativas en la empresa. El tiempo takt es el corazón de cualquier sistema de lean Management.

Takt Time en sencillo significa que tan seguido se debe producir un producto o parte, basado en las ventas para cumplir los requerimientos del cliente.

Sin embargo, no se debe confundir el Takt Time  con el Cycle Time (El Tiempo Ciclo Manual Total), que es el tiempo de trabajo manual necesario para completar el proceso analizado. Como consecuencia de ambos conceptos se llega a un importante parámetro de la Celda/proceso:

N° de operadores=Tiempo ciclo manual total                               -------------------------------                                       Takt Time

Pero no es tan sencillo ya que si bien conocer el Takt Time  es necesario para programar una planta, la habilidad para producir exactamente a takt requiere una gran precisión y eficiencia en conocer la demanda del cliente. La incapacidad de producir hasta takt significará que no se puede satisfacer la demanda del cliente. Las causas de ello puede ser cuestión de instalaciones (equipamiento), velocidad de procesos, personal insuficiente.

Exceder el Takt Time  implica que la planta produce más de lo que se puede vender y eso significa exceso de stock de productos terminados.

Para calcular el Takt Time  es necesario:

1. definir el horizonte temporal para la evaluación del Takt Time 2. determinar el volumen de ventas previsto para el período.3. determinar el tiempo laboral disponible4. calcular el Takt Time  como relación entre el valor determinado entre el punto 3) y

aquel correspondiente al punto2)

Los requisitos  para calcular el tiempo Takt son: por un lado tener respuestas rápidas a los incidentes para estar siempre dentro del tiempo takt. En segundo lugar, disminuir -tendiendo a eliminar- los tiempos de cambio de modelo y de toda la cadena de valor. Por último, eliminar las causas que producen tiempos muertos no planeados.

Ventajas del tiempo Takt

La utilización del tiempo Takt permitirá la sincronización de la producción con los pedidos de los clientes permitiendo a la vez la planificación en flujos. En este caso la sobreproducción es limitada y las existencias también. A través del uso de este concepto, se logra una producción estable, sin interrupciones, donde el ritmo de la fabricación es el tiempo Takt, además de la cadencia regular de trabajo para los operarios. Otra ventaja que se identifica es una simplificación de los procesos de los puestos de trabajo. Por último, hay una identificación rápida de los objetivos conseguidos y como consecuencia una lograda motivación de los empleados del equipo de trabajo involucrado.

Pre-requsitos del tiempo Takt

Para aplicar los conceptos de tiempo Takt es importante revisar previamente los procesos, logrando un equipo de operarios flexibles y polivalentes por otra parte, es imprescindible que tanto los procesos como las maquinarias y equipos sean flexibles dado que ante una variación del tiempo Takt pueda regularse fácilmente.

 Conclusión 

En conclusión, el tiempo Takt es una herramienta poderosa, pero no debería ser cambiado continuamente. Debe ser utilizado según las previsiones de pedidos a largo plazo, más que según las previsiones a corto plazo, diarias o semanales.

Podemos pensar que algunas de estas técnicas son de difícil aplicación cuando los contextos económicos varían interanualmente o los períodos de crisis conllevan a variaciones de demanda difíciles de predecir. Además, si bien hay procesos, tiempos y recursos que pueden controlarse por estar dentro de las paredes de una planta, hay factores que no dependen del fabricante en relación a toda la cadena de valor interviniente en sus procesos productivos.

Lo que ocurre antes de que los productos ingresen a la planta, influirá en el cumplimiento de las entregas, la fiabilidad y la calidad de los productos. La cuestiones posteriores a la producción pueden monitorearse mediante métricas que perciban los cambios en los pedidos de los clientes sea en el volumen como en la canasta de productos vendidos.

Las campañas de promoción o el marketing sin alertar a producción, pueden crear una oleada de demanda, que haga estragos en las plantas mejor preparadas. Hay muchas más medidas a disposición de los fabricantes y muchos recursos para encontrar métricas específicas para cada tipo de ambiente de trabajo.

Un buen fabricante invertirá su tiempo y esfuerzo en adoptar las medidas justas para su empresa – aquellas que les ayuden a resolver los problemas de producción, optimizar la

capacidad, fomentar los márgenes, incrementar la rentabilidad. Un buen fabricante lo mide, lo mejora y lo vuelve a medir. ¿Cómo medirá (y mejorará) usted su éxito este año? Y lo que es más importante, ¿cómo lo medirá el año que viene?