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CHAPTER 5
Product Design and Process Development
5.1 Introduction
Product design takes a long time and a great deal of effort. It is important to target the design programme to minimise time and costs and to plan for it to be successfully completed within allocated resources. Time is very much of the essence, the minimum compatible with optimal development. In a product design plan, there are many activities to be first recognised and then coordinated; some activities are worked in sequence, some in parallel. In particular, multidisciplinary activities are focused in the same direction and coordinated in time. The master plan coordinates the various people and their mini-projects in an overall time and resource plan so that the product design can be controlled. The plan begins with the product design specifications. These include a profile of the product characteristics as defined by the consumer, the structure and composition, safety factors, convenience and aesthetics, and also indicates the manufacturing, processing and storage variables and their effects on the product qualities. Many of these product design specifications start as general descriptions; product design and process development focuses them into definite, quantitative descriptions. In the design process, the product and process development are integrated so that at the end of the design stage there is a product with the optimum qualities, and a process to produce
it. A great deal of time is lost if a food product is designed under 'kitchen conditions' and then has to be redesigned as the process is developed. In food product design: important marketing factors are consumer acceptability, competitive positioning, legal regulations, ethical requirements, environmental mandates and distributor requirements; important technical factors are raw material availability, ease of processing, cost, attainability and reliability of product quality, shelf life, equipment needs, human knowledge and skills; and important financial factors are costs of manufacturing and distribution, costs of further development and the investment needed. These are considered at various parts of the design so that at the end of the product design and process development they can all be included in the feasibility report for top management.
5.2 The design process
The design activities are grouped into steps: 'getting the feel', screening, ball-park studies, optimisation and scale-up of production and marketing, leading at the end to product and process specifications, marketing strategy and financial analysis as shown in Figure 5.1. This allows control of the design process as the consumer, product and process activities are coordinated into small mini-projects with specific objectives. The activities and some of the experimental techniques in the various stages of product design and process development are shown in Figure 5.1. The stages used in this book are ‘getting the feel’, screening, ball-park studies, optimisation, scale-up (production) and scale-up (marketing).
In the design, both the input variables to the process and the output variables of the product qualities are identified early in the developments. The input variables are:
- raw materials: type, quality, quantity;
- processing variables: types of processing, processing conditions. The output variables are:
- product qualities;
- product yields The levels of the input variables that are possible in the production are identified and used in the design experimentation. The level of a raw material (or ingredient) is the percentage in the formulation. Raw materials and ingredients are sometimes differentiated: raw materials as the primary products from agricultural and marine sources, and ingredients as processed materials. In this book, raw materials includes both, and mean all materials used in the process. The levels of processing variables are related to physical, chemical and microbiological measurements and also the achievable and necessary limits set by equipment and environmental conditions. There are limits set on the input variables by the needs of the product, processing and costs; there may be a lower level and a higher level, or just one of these. Identifying these levels early in the design reduces the time spent on experimentation. The product qualities wanted by the consumer are identified and quantified. Usually a range is discovered within which the product is acceptable; this sets the range within which the quality has to be controlled. Again there are usually low and high levels identified for the product qualities. The yield of product necessary to give acceptable costs is identified early in the design to direct the raw material and process experimentation. The design is a continuous study of the relationships between the input variables and the product qualities, so that the final product prototype is the optimum product under the conditions of the process. The two main parts of product design are making and testing the product prototypes, and the two important groups of people are the designers (often called developers in the food industry) and the consumers. The prototype products are tested under the standards set by the product design specifications, so that product testing needs to
be organised along with the product design and the processing experiments. Regularly there is consumer input, to confirm that the product is developing characteristics as identified in the product concept and not developing characteristics which are neither wanted nor needed by the consumer. As discussed in Chapter 1, the product design ends with a final product prototype and a feasibility report:
- defining the feasibility of the product for technical production, the market and the company;
- anticipating the technical and market success;
- assessing the financial feasibility; and
- predicting associated impacts on the company and the market of various levels of product success. Gathering information for the feasibility report is an important part of the design process.
5.3 Steps in product design and process development
Carrying out the design in the five successive steps listed in Figure 5.1 goes some way towards eliminating the mistakes of choosing the wrong design and also making the product on a large scale when very little is known of the processing system. 5.3.1 'Getting the feel' This is a continuation of the development of the product concept and the product design specifications. The processing methods and conditions outlined in the product design specifications are used to make the early product prototypes, and the technical testing methods are examined for reliability and accuracy in testing both the technical product characteristics and also their relationships to the consumer product characteristics. There is a question of consumer involvement at this stage; some people advocate this strongly because it means that there is control over the design; others say that it is faster and just as accurate to use the knowledge of the designers. The choice of no consumer testing depends
variable is considered at high and low levels, and the combinations of these high and low levels for all input variables are tested. In a full design all possible combinations are run, therefore for three variables the total number is 2^3 = 8 experiments. In food formulations, mixture designs are often used because it is impossible to vary one ingredient while holding all the others constant; in mixture designs, the sum of all the ingredients in the formulation must add to 100%. The product designer must always be aware that when they change the content of one ingredient, the proportion of the other ingredients changes, for example reducing the fat content will increase the proportion of other ingredients: carbohydrate, protein or water. With factorial designs and mixture designs, the effects of the various input variables, alone and together, on the product qualities are analysed, and mathematical relationships developed between the input variables and the product qualities. To set up the experimentation and to analyse the results, there is computer software readily available for food product development. Both technical testing and consumer testing of these product prototypes are carried out. The consumers are testing for acceptability and the technical tests are examining the chemical, microbiological, physical and sometimes the sensory properties of the products. Accuracy and reliability are important considerations in this testing, both for studying the effects of the input variables on the product qualities and for developing the quality assurance programme. The total processing costs of these product prototypes are compared to identify the effects of the input variables on the costs, and to check that the costs are within the target cost range.
Think Break 5.
Steps in product design and process development: consumer testing Discuss the advantages and disadvantages of consumers testing the prototypes in 'Getting the feel', 'Screening' and 'Ball-park' experimentation. For what types of products – packaging change, product improvement, product line extension, product innovation – would you use consumer testing and at what stages in the product and process development?
5.3.4 Optimisation Here the aim is to optimise the overall product quality by determining the levels of the input variables which will give the best possible product quality. The problem is that often when optimising one product quality, another product quality is less than optimum. So it is a case of setting the relative importance of product qualities, and for the most important product qualities studying the formulation and processing variables to find the optimum. But the limits that are acceptable across all the product qualities need to be known so that during the optimising experiments none of the other product qualities become unacceptable.
. For raw material formulations, linear programming can be used to optimise a number of product qualities and costs with the amounts of raw materials in the formulation held between upper and lower levels. 5.3.5 Scale-up Scale-up (or ramp-up) of both the production and the marketing is the last stage of the product design and process development. The production scale-up is the in-plant test to verify that the product can be made at the quality and quantity required, and the marketing scale-up is a large consumer test to verify that the target consumers will buy the product and what marketing strategy will encourage this buying. The aim of the processing scale-up is to determine the optimum production process for product quality, product yield, process control and costs. If the previous design research has combined the product and the process, this can be achieved without too many problems. But if the process has been ignored, then there can be disastrous problems. For example, if some of the intermediate materials have never been pumped during the design experimentation, then they could break down during scale-up. The scale-up can be either on a pilot plant or short production runs on the main plant. If it is a new process, or there is to be quite extensive experimentation, then the scale-up is conducted on a pilot or small-scale plant. If the process is only an adaptation of the present production, then the scale-up is conducted on the main production plant. The decisions on the type of scale-up are often much influenced by cost; the production trial can cost a great deal if the product cannot be sold and this restricts the use of the production plant until the final stage. But if there is no investment money to build a pilot plant then the production
In Case Study 5 are some comments on food design for the future from an Italian design journal, to start you thinking about the development of food design. Certainly today there is a need to determine the direction of food design both for food ingredients and consumer products, and also for the fresh products which are being designed on the land and in the water.
5.4 Product testing
Product testing is an integral part of the product design and process development as can be seen in Figure 5.2. Case Study 5. Towards a Food Design The food product development project passes from a traditional approach aiming at the adjustment of natural food, to an approach based on consumer needs, and then to an approach implying the interpretation of food technology potentialities in the framework of the food culture of eaters. Food design aims at closing the gap between what is culturally acceptable as nourishment and the extreme technological situation of foods consisting of the most artificial nutriments. It must combine artificiality with quality by integrating into the food development project all aesthetic, sensory and symbolic dimensions, along with what has been handed down and the future developments of custom and food culture, to develop 'edible objects' detached from natural products but offering the same degree of quality and richness. Besides, it must ensure - between those who eat and make food - a mediation, not just a formal one or based on a naturalistic food, but a deeper one, asserting the technological identity of food by seeking, in the ancestral food culture as in the chaos of present day behaviour, a poetical spirit that may make it more valuable. (From François Jégou (1996) 'Design and food; object-food and food raw materials', Stileindustria, 2(6), June, pp. 40-1.)
Figure 5.2 Testing activities & techniques in product design and process development PRODUCT DESIGN SPECIFICATIONS ________________________________ ____________________________________ Technical Consumer Costs 'Getting the feel' Setting up Ideal profiles Company costs Reliability Training Standard tests Profile tests Cost analysis Correlation of technical/consumer tests PRODUCT 'MOCK-UPS' Screening Technical Product comparison Raw materials Sensory cost limits Product testing Difference testing Materials cost comparison ELEMENTARY PRODUCT PROTOTYPES Ball-park studies Technical Acceptability Preliminary Sensory product costing Statistical testing Preference panel Spread sheets ACCEPTABLE PRODUCT PROTOTYPES Optimisation Technical Product Improvement Product, Sensory packaging, Storage process costing Control testing Use tests Cost comparison Shelf life tests Competitive comparison OPTIMUM PRODUCT PROTOTYPE Scale-up Quality assurance Buying predictions Yields Marketing study Materials Equipment Raw material testing Market survey Equipment comparison Process study Attitude panel Total costing: Product study Large consumer test capital and operational
FINAL PRODUCT PROTOTYPE PRODUCT AND PROCESS SPECIFICATIONS MARKETING STRATEGY FINANCIAL ANALYSIS FEASIBILITY REPORT
5.4.2 Shelf life testing Testing shelf life is important in food design because there is usually a target shelf life to be achieved for transport and storage in the distribution chain as well for storage of the product by the consumer after buying. From previous knowledge, some predictions can be made early in the design on the possible shelf life; foods can be divided into short-life products (up to 10-14 days), medium-life products (up to eight weeks) and longer-life products (up to 1-2 years). The possible deterioration reactions in the food are identified, for example chemical reactions like browning and loss of colour, and microbial growth of food spoilage organisms, moulds and yeasts. It may be necessary to carry out accelerated tests under severe conditions to identify exactly what the deteriorative reactions are. Shelf life testing needs to be started as soon as possible in the prototype development, usually at the start of optimisation experiments. Shelf life testing takes time and can be the critical activity controlling the completion of the project. The variables need to be identified
- usually temperature, humidity and surrounding atmosphere in storage; vibration, handling and contamination in transport. Factorial designs are again used so that the quantitative effects of changes in the storage and transport conditions on product quality can be measured.
Think Break 5.
Product testing: shelf life The 'use by' or 'best by' dates on food products are indicative of the shelf life of foods. The shelf life is the length of time before the consumer can recognise a change in quality or the product becomes unsafe. Look at some 'best by' dates in the chilled cabinets of the supermarkets and note the 'best by' dates for different types of foods and brands. Did the information on the package include storage temperatures? How would you use this information for setting the conditions for shelf life testing of two new products: (1) natural active yoghurt (2) vacuum packed sliced salami? ( See Lewis, H. And Dale, R.H.(2000) ‘’Chilled yoghurt and other dairy desserts’ in Man, C. M. D. and Jones, A. A. (eds,), Shelf-Life Evaluation of Foods, 2 nd. Edition, Gaithersburg, Maryland: Aspen Publishers pp.89-109.)
5.4.3 Sensory evaluation Sensory evaluation can be carried out by expert sensory panels or by consumers. Traditionally in product design, the expert panel determined the differences between prototypes and the direction of the differences, while consumer panels evaluated the acceptance of products or preferences between products. This meant that consumer input did not take place until the final stages of prototype development. But with the acknowledged importance of the early stages of product design, consumer panels are now used to guide the design. Such panels are used in screening the ingredients, determining the product characteristics and their strength in the ideal product, developing and optimising the product profile of the product prototypes, and optimising products for acceptance and cost. Care needs to be taken when choosing the “consumers” – are they the people who buy the product, who prepare the meal, who eat it? A trained panel may consist of between four and ten people, but consumer panels are larger, comprising at least thirty people depending on the type of testing. The members of a trained panel after a month or longer training are able to score the product qualities reliably and accurately. Consumer panels are not trained, but are representative of the users of the product. Initially consumer panels were considered 'too much work' and expensive, but experience has shown that this is not so. The size of the consumer panel increases throughout the design as the importance of making the right decision becomes critical and the penalty for a wrong decision becomes larger. In product formulation, it can consist of 15-20 consumers, rising to 50- 100 consumers during the final processing trials and 200-300 for the final product prototype, while in some large markets with greater variability it may be even more. The smaller panels are useful when some depth of knowledge is needed though they are not a statistically valid method of determining how many people in the market will buy the product. But over the years, it has been shown that there are significant correlations between the verdicts of the consumer panel and the larger consumer test if the members of the consumer panel have been selected carefully and are representative of the market. Consumer panels are used for seeking in-depth information about the product's characteristics and uses. The aim is to obtain as much detailed information as possible so
Table 5.1 Basic costs for producing and distributing a product Some of the manufacturing costs comprise raw materials, packaging, labour, depreciation of equipment, electricity, steam, gas, water, waste disposal and plant overheads. In many companies, during the product design and process development, the raw materials and direct processing costs are continuously determined and are part of the design. For example, in the linear programming models for product formulation there is usually either a total cost constraint for the raw materials or the aim is to minimise cost. Standard percentages or ratios on these materials and processing costs are used to predict the company costs. This has to be carried out with care, especially with innovative products or new markets where some of the marketing and distribution costs are unknown - these may be found to be too high only at the later stages of the project and prevent the launch. At the end of the product design and process development stage, there should be reasonably accurate forecasts of production and distribution costs and some indication of the probable marketing costs. Manufacturing costs Raw materials cost Direct processing costs Fixed costs Plant overhead costs Distribution and marketing costs Physical distribution costs Market channel costs Promotion costs Sales and selling costs General company costs Administration costs Development costs Financing costs
There are three important general activities in product design: product formulation, packaging development and processing development.
5.5 Product formulation
Many food products are made by combining raw materials in specific proportions in a formulation, and research on the effects of various formulations on product qualities is common in product design. In systematic formulation there are five steps:
- Set the product qualities required,
- Find data for the raw material compositions, qualities and costs,
Think Break 5.
Product testing: fruit drink powder development Fruit drink powders are dissolved in water to give a refreshing drink. These drinks are popular with children, and are also used as cheap drinks for large parties. 1.Identify the ingredients in fruit drink powders by reading the labels on some powders available in the supermarket or by searching in the internet e.g. ‘Ingredient manufacturers turn powder into health gold’ by David Feder. http://www.foodprocessing.com/articles/2008/370.html Sighted 14/11.2008.
- Identify the important product qualities in such powdered drinks, and suggest how you might test these product qualities with laboratory testing, with trained sensory panel testing and with consumers.
- Fruit drink powders are produced by mixing the ingredients so that they are evenly dispersed and then they are packed into sachets. Identify important factors in this processing and packing. Outline the method you would use to develop a fruit drink powder, combining Figures 5.1 and 5.2 in one diagram.
In formulation studies, the important development in the last ten years has been the use of the computer. First, there is the raw material database on the computer; this started by detailing the chemical and nutritional compositions of different raw materials but has expanded to other properties such as microbiological quality, sensory qualities and to the effects of raw materials in processing, where this information is available. For companies Example 5.2 Raw materials for Thai Fermented Sausage (Nham)
- Meat System: fresh lean pork and pork-skin, held at ambient Thai temperatures for three hours after killing.
- Curing agents: sodium chloride, sodium nitrate, sodium tripolyphosphate.
- Seasonings: white pepper, fresh garlic.
- Carbon sources for fermentation: jasmine rice (cooked), glucose.
- Starter cultures: Lactobacillus plantarium, Lactobaccillus brevis, Pediococcus cerevisiae, Micrococcus varians.
- Sausage casings: cylindrical tubes, 22.5 mm diameter, 30 cm long, made from laminated 15 micron uncoated nylon and 50 micron linear low density polyethylene. Limits on raw materials Meat system was set at 80% ground meat 20% sliced pork skin. The low and high levels for the other ingredients and starter cultures were: Raw materials % meat system Starter Cultures cfu/g meat system sodium chloride l ,4 Lactobacillus plantarium 0, 10^6 sodium nitrate 0.01, 0.03 Lacobacillus brevis 0, 10^6 sodium tripolyphosphate 0, 0.5 Pediococcus cerevisiae 0, 10^6 minced garlic 3, 7 Micrococcus varians 0, 10^6 white pepper 0, 0. cooked rice 5, 8 Screening experiments A Plackett and Burnam experimental design was used to screen these raw materials. From this, the important raw materials affecting the qualities of the Nham were identified as the four starter cultures and the rice, and in further experiments these were studied at different levels and under different processing conditions. Glucose as another carbon source was also studied. The other ingredients were fixed: sodium chloride 3%, sodium nitrate 0.02%, sodium tripolyphosphate 0.3%, garlic 7.0%, white pepper 0.05%. Wiriyacharee, P.,( 1990) The systematic development of a controlled fermentation process for Nham, a Thai semi-dry sausage , Ph.D. thesis, Massey University, New Zealand
with a narrow range of products, this raw materials database can be used in all product development projects as a starting point for formulation; in other companies with a wide- ranging product mix there may be need for two or three databases. The database is only useful if it is kept up-to-date and is also related to the company's buying policy. The database can be used to build and analyse various formulations to see how they fit the criteria for the product qualities, the costs and the processing. This can be done quite simply using computer spreadsheets. There are also expert systems available which provide a decision support framework made up of two parts: a task part containing the distinct problem-solving steps involved in creating a formulation, and a physical part with the specific knowledge about the properties of the raw materials and the processes involved. As more information is obtained from factorial experimentation, mathematical relationships between the raw materials in the formulation and the product qualities are developed and these can be used in such techniques as linear programming.
5.6 Packaging development
Packaging design at this stage concentrates on the packaging of the individual product; the outer packaging research is only related to decisions regarding size and to the protection required during distribution. The design of the packaging for the individual product is based on the needs of the consumer and the requirements of product preservation and protection in the product design specifications, but it also considers the process and the distribution, as well as the needs of retailers and the environment.
Think Break 5.
Product formulation: natural fruit ice-cream For developing a formulation for natural fruit ice-cream, identify the important raw material variables and the important product qualities. Relate each raw material to a product quality(ies); for example, lecithin, an emulsifying agent, stabilises the oil/water emulsion and gives smoothness to the ice-cream. See: The Science of Ice Cream by Chris Clarke, 2004 Published by the Royal Society of Chemistry.
