Framework for capacity analysis and design a cellular manufacturing system-ABB Nasik.

Abstract

Our Business Area's most major concern is : How to deliver the product ON TIME to the customers? The strategic goal of ABB's business area "medium voltage switchgear" is to achieve 75 % on time delivery . Presently the on time delivery rate is 25 %. Our capacity in the year 1993-94 was 4 breakers ( different varieties) per day and equal numbers of matching cubicles. Our long range ( next 2 years) strategy ,is to reach 3000 breakers per annum i.e. 10 breakers/day. So, the above question leads to two dimensions of the problem : 1) Do we have sufficient resources to deliver the product on time ? 2) For achieving the goal , What are the constraints and How to resolve them? For answering these questions , I have divided my work in two stages. Stage 1 : A study of capacity gaps analysis for existing and future production and to develop a decision support system. Stage 2 : Reduction in throughput times by forming cells and adapting cellular manufacturing. STAGE 1 The machine shop capacities, with respect to types of machines, is computed here with . All the existing components made in house, for all varieties of products(breaker 4 varities and cubicle 6 varaties) , are considered . The system is developed in such way that once the quantity (Annually ) of products to be produced is entered, the information regarding Required Man Hours, Available Standard Man Hours and Available equipment hours, is obtained instantaneously , for different groups of machines . This information is very useful for measuring the existing capacity and predicting future requirements for different product mixes. The product mix percentage has been forecasted by taking into consideration no. of manufactured units over last three years, product life cycle stage and current order booking trend. Decisions for alternative capacity generation thus, can be made easily by seeing the various gaps . Batch quantity, operation efficiency and units of product mix to be manufactured during the year are variables. This will help in simulating all the possibilities This will help us in quoting realistic customer delivery dates and will help in improving customer satisfaction by choosing right order mix. STAGE 2 It is proposed to adapt cellular manufacturing in place of the traditional way of working. The proposed system will enable a family of components to be manufactured on a group of machines , normally without the component moving out of the cell. The formation of the cells was done by considering : Group Analysis ( intra- department) and Line Analysis ( intra- cell). Each cell completes all the components it makes ( with very few exceptions) ,with no backflow and cross flow (between cells) and no need to buy any additional equipment's for meeting current requirements. This was done by matrix resolution of machines and the operation roots of the components. Four cells were formed. Also, the capacities of each cell with respect to number of units ( breaker/cubicle) it can manufacture for different product mix, was computed. The constraints for each cell are identified for increase in the production volumes. Change Over Flexibility was kept at the back of the mind , while forming cells. For example, cell 1 can accommodate 95 % of the new product's components, which we are launching by end of current year ( model - HA2) . And cell 3, which contains more disposable machines, is used for the product which will be phased out within next two years ( model- MOCB). Space is generated ( with the implementation of new layout) near cell 1 , considering the future requirements. After implementing the proposal , only one component out of 175 components will have to move in between two cells and only 2 out of 175 components could not be accommodated in any of the cells. The cell outputs will be absolutely predictable. Space saving of 249 sq. met. is achieved. Although this does not decrease the actual machining time , it will enable the component to progress speedily from machine to machine , either individually or in small batches, thus reducing considerably the inter operational losses. The set up time will reduce since a fixed set of components will be produced from fixed a set of machines. The throughput time will therefore reduce, since all hold ups will be removed, and the level of work in progress will be kept to a minimum. This will enable a more reliable delivery date to be quoted, minimize stock investment and greatly simplify production control. The management is fully committed to adopt this system. Our all parent companies have cellular layouts. With the proposed cells , the manufacturing capacity will go upto 5.92 units / day ( breakers and cubicles). Which is very near to our this years target of 6 units /day.