Operations Management Assessment

Please read the attached case ‘Fresh Salads Ltd: The Iceberg lettuce harvest’ carefully and answer the following questions in a 1500 words report. To answer the questions you will need to apply Operations Management models. The assignment is looking for the application of Operations Management. You may want to use Operations Management literature to help you with the assignment. However, Harvard referencing is required.

The questions simply asks to extract facts from the case and to briefly explain your decision on the process type and layout

Questions: 1- What are the inputs and outputs of the transformation process described in this case? 2- What are the main operations objectives for the macro-operation? 3- How would you describe the type of process and the layout used in this operation?

Fresh Salads Ltd: The Iceberg lettuce harvest

* Introduction
Fresh Salads Ltd is an important division of a privately-owned farming company specialising in vegetable growing and distribution. Its most important customer group is the major UK supermarkets which require fresh produce to be delivered to them 364 days a year. The company has all the staff, expertise and specialised facilities needed to supply these supermarkets throughout the year. One of the most important products of this company is Iceberg lettuce, which is grown in England during the summer and in south-east Spain during the winter. Iceberg lettuces are dense and round, but are easily bruised so have to be harvested with great care, after which they are stored and transported in chilled conditions to avoid deterioration. From the time of cutting, they must be packed quickly to minimise water loss and taken rapidly to a cool store. Market demand varies greatly, dependent on the season and on weather conditions, with demand rising rapidly in periods of hot, dry weather and in the preceding day. Supermarkets rely on weather forecasts to predict demand for salads and fresh sandwiches.

* The harvesting rigs
The company has developed specialised machinery to assist in the harvest of millions of Iceberg lettuces every year. Each of the company’s six Iceberg lettuce picking machines (known as ‘rigs’) is a large mobile factory which is mechanically powered to move very slowly across the enormous lettuce fields, at a speed and direction controlled by the supervisor using a simple joystick control. The rig runs on caterpillar tracks which allows it to cross the soft, deep peaty soils on which lettuces thrive. However, in very wet conditions, this very heavy piece of equipment can get stuck and may need assistance from an additional crawler tractor. At the very back of the rig is attached an open-fronted road trailer, into which the trays of packed lettuces are carried and stacked. This trailer can be released when full, and attached to a four-wheel drive tractor for subsequent transportation to the company’s local cold store. Another trailer is then connected in its place to allow picking to continue uninterrupted.
Each crew (picking team) comprises 17 people and a supervisor; there are nine cutters, five packers and three people preparing cardboard trays, labelling the individual supermarket lettuces and carrying completed trays and crates to the trailers. The supervisor, who is fully responsible for product quality and output of the rig, also provides assistance at any point on the rig to relieve any short-term bottleneck and to cover any short period when an operative need to leave the rig. The crew members are paid piecework, and usually work eight-hour days (plus breaks), although overtime may be necessary on very busy days in mid season. Crew members of the most successful teams can earn more than double the UK hourly minimum wage, but this requires sustained effort and concentration, and cooperative crew behaviour.

* The picking process
The nine cutters work on the ground in a wide line just in front of the rig, which slowly moves towards them. They stand astride the rows of lettuce, working slowly backwards. The average cutting speed per person, in good conditions, is eight seconds per iceberg lettuce. Within this cycle time the picker selects and cuts each lettuce using a sharp, slightly hooked knife, trims away the outer leaves (which are often muddy and/or damaged), and the drops the prepared lettuce into a polythene bag pulled from a bundle attached to the cutter’s waist belt. The cutter can choose to leave uncut any lettuces exhibiting defects, for example, under-size, poor shape or damaged, and these are later ploughed back into the soil. They are also very skilled at judging lettuce weights, and will avoid under- or over-sized specimens. The best-quality wrapped lettuces are then thrown carefully forward to a packer. Others are thrown further forward straight into plastic crates of 20 for subsequent industrial processing, depending on quality. These are known as ‘process grade’ and are used to make prepared salads and bulk chopped lettuce for the sandwich industry. In persistently wet weather, the average picking rate can slow by up to 25 per cent, as a result of a combination of mud slowing the picking and packing process, rigs getting stuck and a general deterioration in morale of the crew.
The five packers sit on seats attached to the front of the rig, in front of the pickers and just off the ground. They seal the bags with tape, and place the lettuce in a single layer in cardboard trays, selecting (grading) them – the best quality for the supermarkets in trays of 10, the remainder for wholesale markets in trays of 12. On average, this task takes five seconds per lettuce. The full trays are then quickly pushed forward to the final group of employees who work further back on the rig, higher up and level with the trailer floor.
These three workers have several tasks. Firstly, they have to erect the cardboard trays from flat ‘cut and creased’ blanks which the company buys in from an outside supplier of cardboard packaging. This tray preparation entails a folding and tucking action, and one skilled worker can make and stack the trays in an average of about seven seconds each. Typically, half of this person’s time is spent on this activity, and the remaining time on labelling.
The next task is to label all the supermarket lettuces. Self-adhesive labels are provided on a long roll, and are simply peeled off and stuck on each lettuce bag. These labels customise the lettuce for individual supermarkets and also provide the bar code and sell-by/use-by dates. Although they have to be positioned carefully with minimal creasing, a skilled worker can apply a label about every two seconds. On completion, each tray is then pushed forward, ready for conveyance to the trailer by another worker.
Each filled tray or crate has to be carried from the deck of the rig into the transport trailer, where it is stacked. Although the walking time for this action depends on the extent to which the trailer has been filled. An average time is approximately 15 seconds, which includes the time needed to return for the next tray or crate. This is the heaviest task, so the three workers rotate the jobs on the upper level of the rig. The supervisor is based here too – weighing equipment and quality records are kept at the back of the rig – so is able to assist with these jobs when needed. Trailers are changed approximately every two hours, but this does not stop the operation of the picking, packing or labelling part of the rig. Two workers are needed to uncouple the trailer and reconnect the empty replacement. This takes approximately 10 minutes.
On average, during a normal working period, each worker uses about five per cent of the time for personal needs and for occasional activities; such as collecting packaging material. Breakdown time averages approximately two per cent of the available time, and this is usually used for cleaning and preparation.
Although the supervisor is able to assist others when the need arises, he or she spends about two hours a day on quality assurance. Statistical process control (SPC) is used to ensure that lettuce weight is within the requirements of each customer, and samples are inspected to ensure that their appearance remains within tolerance. Records of quality and output are maintained per rig.

* Output statistics
During a busy period of sustained good weather in August, the average daily (eight hours) output from each rig was as follows:

Supermarket 1800 trays Wholesale 230 trays Process 200 trays