Inventory control

With any manufacturing facility good inventory control is an absolute essential. It is estimated that it costs up to 25% of the cost value of stock items per year to maintain an item in stock. Proper control systems have to be used to ensure that there is sufficient stock for production while at the same time ensuring that too much stock is not held. If stock levels are high there are costs associated with damage, breakage, pilferage and storage that can be avoided.

Work force management

Work force management is required in order to ensure that there is a suitably trained and experienced work force that can apply the engineering processes, tools and facilities.
The important aspects of work force management are:
• work and method study
• work measurement
• job design
• health and safety.
The production manager has to establish standards of performance for work so that the capacity of the factory can be determined and so that the labour costs of products can be calculated. Work study, method study and work measurement activities enable this to be done, as well as help to promote efficient and safe methods of working. The design of jobs is important in respect of worker health as well as effective work. Good job design can also make the work more interesting and it improves employee job satisfaction, which in turn can improve productivity.

Quality control

Quality is a key objective for most engineering companies. It is especially important to the production function that is actually manufacturing the product for the customer.
Quality is generally defined as fitness for purpose. In effect this means meeting the identified needs of customers. Thus it is really the customer that determines whether or not a company has produced a quality product, since it is the customer who makes an assessment of the perceived value of a product and is then either satisfied or dissatisfied.
This does bring problems for manufacturers since customer perceptions of quality vary. As a consequence some customers will be more satisfied with a product more than other customers (the ultimate test is probably whether a customer will make a repeat purchase or decide to purchase from another supplier). Because of the subjective nature of quality assessment, manufacturers often attempt to use more objective criteria for assessing fitness for purpose. This often includes:
• design quality
• conformance quality

• reliability
• service/maintenance.
Design quality is usually the joint responsibility of a company’s marketing or customer liaison function and its R&D function. Design quality relates to the development of a specification for the product that meets a customer’s identified needs.
Conformance quality means producing a product that conforms to the design specification. A product that conforms is a quality product, even if the design itself is for a cheap product. That may seem contradictory, but consider the following example. A design is drawn up for a budget camera, which is made from inexpensive materials and has limited capability. If the manufacture conforms to the specification then the product is of high quality, even though the design is of low quality compared with other more up-market cameras.
Reliability includes things like continuity of use measured by things like mean time between failure (MTBF). Thus a product will operate for a specified time, on average, before it fails. It should also be maintainable when it does fail, either because it can easily and cheaply be replaced or because repair is fast and easy.

When an engineered product fails or becomes unreliable, it will require service. Service relates to after-sales service, the realization of guarantees and warranties, as well as the need for ongoing maintenance in order to ensure that performance remains within specification.
Quality control is concerned with administering all of these aspects. In the UK there are general standards for quality systems, the most relevant one here is BS 5750 and the international counterpart ISO 9000. The activities that make up a quality control system include the following:
• inspection, testing and checking of incoming materials and components
• inspection, testing and checking of the company’s own products
• administering any supplier quality assurance systems
• dealing with complaints and warranty failures
• building quality into the manufacturing process. ,
Whilst many of these activities are performed in order to monitor quality after the event, others may be carried out to prevent problems before they occur and some may be carried out to determine causes of failure that relate to design rather than manufacturing faults.