Methods for assessing time and cost in a food supply chain
This chapter presents an overview of supply chain time – cost mapping (SCTCM), a framework which any organization can deploy which will enable them to gain greater visibility of both time and cost in their supply chain operation. The framework is underpinned by incorporating the tools and techniques of time-based process mapping and activity-based costing. It provides an organization with a holistic perspective of supply chain time and costs associated with a single product. The SCTCM can be used to identify and evaluate waste (non-value adding time) and provide additional insight into the costs associated with the supply chain activities consumed by a product. The framework provides a base case which can then be used to measure the impact of different improvement scenarios in terms of changes in total time and cost and highlights the impact of trade-offs between the individual activities that make up the supply chain process for a given product.
Organizations are constantly involved in ventures to improve their operational effectiveness. These ventures can take many forms such as business process re-engineering, TQM, lean manufacturing and Six Sigma. Many of these efforts take place in a relatively localized manner without necessarily having the complete supply chain picture. This can lead to changes in the process that can benefit some functions in the organization but unfavourably affect others, leading to local optimization or situations where a project improves certain aspects of the operation (e.g. lead time) but adversely affects others (e.g. costs). To avoid this, it is necessary to have visibility of the supply chain and to understand the interactions between different functions and variables.
This chapter presents a framework designed to provide increased visibility of time and cost through the supply chain by reconciling the techniques of time-based process mapping (TBPM) and activity-based costing (ABC). The framework is intended to help companies evaluate the costs of waste in their processes and to identify key areas for process improvement for the supply chain as a whole. The framework was designed specifically for companies in the food and drinks industry and it is applicable to all users across the entire range of supply chain operations. The tools contained in the framework will enable different users to gain the appropriate level of supply chain information that they require to improve the efficiency and effectiveness of their supply chains.
The chapter is written as a ‘how to’ guide, providing the reader with the requirements to implement the framework. First we describe the framework, discussing each of the stages and providing advice on their use. A case study is then used to exemplify the use of the framework and to discuss some of the challenges and opportunities that arise from its application. Finally, we highlight the benefits from previous uses of the framework and present conclusions on its application.
The supply chain time – cost mapping (SCTCM) framework consists of six stages (see Fig. 12.1). Stage 1 is project definition and involves setting aims, objectives and scope for a project. Stage 2 involves a mapping of the processes in the supply chain. Stages 3 and 4, which can take place in parallel, involve the collection and analysis of time and cost data, respectively. The information arising from this analysis is used in stage 5 to create a cost–time profile. Finally stage 6 involves identifying opportunities and defining the next steps.
This first stage is crucial to the success of the process. The initial focus is to appoint a project champion, establish the principle aim of the project, develop a set of supporting objectives, agree the scope of the project and its boundaries and identify the resources needed to undertake the project.
The aim of the project needs to be unambiguous and concise, with success criteria to provide key reference points for the project team. The objectives (to reduce cost, to map time, to identify waste, etc.) must be aligned with the overriding aim of the project. The scope of the project should include the unit of analysis (e.g. a single product, a product family) and the timeframe of the study. The supply chain processes should also be included.
Once these fundamental factors have been established, the members of the project team can be appointed. The project team will generally comprise a permanent core team (around six in number including the project champion) and will be augmented with subject matter experts as the need arises. The team may be made up of both internal and external members depending on the supply chain processes included in the scope. If the scope of the study crosses organizational boundaries then appropriate confidentiality agreements will need to be put in place.
Having agreed the scope, the next stage is to identify and record the relevant supply chain activities for the product in question. The key consideration at this point is the level of detail required; data should be captured at the lowest possible level (task) as the task data can then be aggregated at a later date into activities and process, depending on the level of visibility required. The output at this stage will be a supply chain map detailing the activities in the process. This map will provide the essential backbone of the study and act as a key enabler of the cost collection exercise.
The mapping process begins by physically walking through the process from beginning to end and it is recommended that you are accompanied in this stage by each process’s owner. This is an extremely important activity, as by observing the processes you can see first hand and gain an understanding of the time and resources consumed by the product as it travels along the supply chain. It is important to capture and record the inputs (e.g. raw materials, equipment, people), controls (e.g. production schedule, budget) and outputs (e.g. work in progress, finished products) of every activity. This is crucial in terms of being able to cost each activity and identify the changes to product form as it passes along the supply chain. The latter point is extremely important in food and drink supply chains, as measurable units at each process stage may be different; for example, the unit of analysis may be a pack of cooked meat weighing 100 g, but at the beginning of the process it would have been a live animal. Once the map has been completed it should be validated with each process owner and changes made to ensure accuracy.
The key objective at this stage is to identify how time is spent in the supply chain and to assess where time is not adding value. It is important here to establish our operational definition of value, which is based on the Gregory and Rawling (1997, p. 31) definition which states that: ‘Value is a property of a product or service that the customer cares about and would be willing to pay for’.
|Value-adding examples||Non value-adding examples|
|1. The customer cares about the change||Taking an order
Assembling a product
|2. Physically change the item||Most manufacturing processes (e.g. sterilization,blending, cooking)||Storage
Waiting for decisions
|3. Right first time||Maintaining quality standards
Delivery on time in full
The activities mapped from the process map together with the time split between value and non-value adding activities will be used to generate a time-based process map (TBPM). A TBPM is a stacked-bar chart that illustrates the sequence of activities; each bar represents an activity and for every bar the proportion of value and non-value adding time is identified. It is important to validate the TBPM with the activity owners as the split between value adding and non-value adding activities could be a contentious one based on the criteria used to define value. Figure 12.2 illustrates a TBPM for a distribution process.
This stage focuses on collecting and analysing both financial and non-financial data associated with the unit of analysis as it travels along the supply chain. It is essential to capture both direct and indirect costs and to identify the accounting systems used to produce the cost data as well as the accounting policy and procedures of the organization which are used to calculate the cost of the product.
It is important to identify the relevant sources and providers of financial information and a completed process map will help to enable and facilitate the collection of the data. Key data sources to consider are the bills of material for direct costs; departmental budgets and monthly operational reports will provide visibility of standard costs, indirect costs and production volumes. Assumptions underpinning the allocation, apportionment basis and indirect absorption rates will be contained in the accounting manuals and operating procedures of the organization.
The level of cost detail may also differ along the supply chain based on the cost unit for each process such as cost per tonne, per pallet, per case or stock keeping unit; it will be necessary here to collect conversion rates, for example the number of cases per pallet. These conversion rates are important, as equivalent units may be employed to cost the unit of analysis along the supply chain as in the case of meat price per kilogram. If the scope of the project extends beyond one organization, access to cost information may be difficult to obtain without an open book agreement between the parties involved. If this is not available then agreed contractual rates will have be used.
The purpose of the translation cost matrix is to translate cost information into a format to cost the supply chain processes identified by the project’s scope and the associated activities which are consumed by a product. The major inputs to the translation cost matrix are the outputs from the cost collection exercise and the time-based process maps, together with additional financial information collected by interviewing operational and finance people, supported by on-site observations collected during the process mapping, to determine the appropriate resource drivers that will enable indirect costs to be pointed to supply chain activities. Cost drivers are then used to calculate the consumption of costs by the unit of analysis.
The cost–time profile (CTP) presents graphically the relationship between the cumulative time and cost consumed by the individual activities which make up a process. Time is measured on the X axis while cost is measured on the Y axis. The outputs from the TBPM and the cost translation matrix are the inputs needed to construct a CTP; an example is illustrated in Fig. 12.3.
The CTP can be used to illustrate the current situation, flagging up those activities which consume either a high proportion of total process time or cost, or both time and cost. The graph can also be used to compare a number of scenarios mapping them against the original curve to illustrate changes in cost and time for each scenario.
The aim of the SCTCM is to provide time and cost information to enable practitioners to make decisions with regard to the management of resources deployed in their supply chain operation. This information is presented in a very visual way using charts and tables which illustrate the supply activities that generate the waste and their proportion of the total cost of a product. This allows practitioners to identify and quantify those supply chain activities which are generating non-value adding time and cost, providing the opportunity for managers to focus and prioritise targeted initiatives that can then be deployed to reduce waste and cost. The framework can be used to highlight the potential trade-offs between activities by understanding the cause and effect relationships between activities and quantifying the potential implications for the whole supply chain if changes are made to individual activities.
The case study company is a large multinational with average sales exceeding €1.7 million. The company supplies spices, herbs and flavourings to retail, food service and food processing markets. Owing to confidentiality issues it was agreed to omit any direct reference to the company or its products.
The study covered two retail products sold in the French and UK markets. These products were blended ingredients packed in jars; one of the products is blended, packaged and sold in France (called product FR-1), while the other is blended in the UK, packaged in France and sold in the UK (called product GB-1). This study covered the processes involved in planning, sourcing, manufacturing and distributing each of these products, from the point of arrival of the materials through to the final delivery at the retailers’ store. The main objectives of the study were the following:
The project, conducted by two researchers, involved mapping and analysis of the processes in the supply chain. In order to facilitate data collection and analysis, the researchers decided to divide the project into five stages: data collection, primary analysis, validation, secondary analysis and feedback. Table 12.2 presents each of these stages, showing the main methods used and the time required at each stage.
At a general level, the internal supply chain for the two products is essentially the same. The main difference is that packaging is only conducted in France. Hence the UK product has to be transported to France for packaging. Figure 12.4 presents a general overview of the main stages required for both products.
At a more detailed level, the processes have some differences, particularly at the sourcing and distribution stages. For this reason the time consumed at each stage varies substantially between the two products as can be seen in Fig. 12.5 and Fig. 12.6, which show the top-level time-based process maps for GB-1 and FR-1, respectively, indicating value added time (VA), non-value adding time (NVA) and average storage time (stock). These figures show that the process for GB-1 has a total duration, from sourcing of materials to delivery to customer, of 138 days, compared to 95 days for FR-1. The main areas that account for this difference are warehousing and distribution.
Planning is essential for determining the flow of products along the supply chain. The planning processes for both products are very similar, as would be expected. These processes were not analysed from a time perspective because they take place at different timelines which are not necessarily aligned with the physical processes. In both processes there are a number of inputs that feed the forecast, such as seasonality, promotions and market inputs. Once the forecast is generated, specific plans are produced for the different stages in the process. In France the process includes the planning of the packaging lines which are not present in the UK.
Raw materials are sourced from around the world. In the case of GB-1, the pre-sterilized raw materials are delivered directly to the factory; for FR-1 herbs and spices are delivered at the port and then transported to the factory. Both sourcing processes consume relatively large amounts of time as a proportion of the total supply chain, 22% for GB-1 and 50% for FR-1; the main reason for this is the amount of raw materials stock held for both products. The process for FR-1 is considerably longer than that for GB-1; the main reason for this is that it covers a larger scope with the delivery at the port, rather than delivery at the factory.
Packaging only takes place in France and all GB-1 blended in the UK is sent to France for packaging. Similar to the sourcing of raw materials, the vast majority of time in this process is consumed in storage. Different quantities are held for each of the four packaging materials, with labels being the highest, with about 40 days’ stock on average.
The blending processes for both products are very similar and consume only a few hours. Most of the time consumed at this stage is in waiting for quality control analysis or simply in storage. In the case of the product blended in the UK, transportation to France for packaging is required, consuming an estimated three days. Packaging for both products takes place in France. The actual packaging process is very swift, taking only a few minutes; the only difference between the two products is that GB-1 has to be returned to the UK for distribution.
The delivery processes in France and UK are substantially different. In France, products are held in two distribution centres (DCs), from where they are transported by forwarders directly to the store. The sales force is responsible for laying out the product directly on the shelves. In the UK, the product is initially held in the DC and then moved to a network of merchandisers responsible for delivering the product in the stores and laying it out on the shelves.
To compare product costs, it is necessary to start by exploring the costing methods and accounting procedures employed for each product. This is presented below following the same framework used for the process analysis (source, make and deliver). It must be noted that the UK division does not have a single integrated supply chain costing system that tracks the products from receipt of raw materials through to the delivery of the finished product to customer. Table 12.3 summarizes the costing methods and accounting procedures used for both products at each stage of the process.
|GB-1 (UK)||FR-1 (France)|
|Source||Raw materials||Raw materials|
|This product is a blend of four ingredients which are bought from a range of suppliers presterilised and delivered into a warehouse in the UK.
A standard costing approach is used for raw material inputs based on the quantities indicated in the bill of materials (BOM). The standards are reviewed quarterly, to adjust for factors such as currency fluctuations, seasonality and weather conditions that can affect the price of raw materials.
Procurement and inbound logistic
Procurement costs associated with raw materials are not included in the standard cost.
They are accounted for as an indirect cost in the ABC calculations and charged to the blend during the blending process.
|FR-1 is a blend of seven different ingredients. Raw materials are not presterilised and delivered into the inbound warehouse.
Standard costing is used to calculate the cost of the raw materials as specified in the BOM. The standard costs are reviewed quarterly as in the UK.
Procurement and inbound logistic
The total costs of both procurement and inbound logistics activities are averaged out over the total volume of raw materials received to give an average cost per kg for each activity.
The cost of the blend is calculated using the standard cost of the raw materials plus the cost of packaging. A standard 3% allowance cost is built into the blend cost to account for normal loss during the production process. The blending process costs are formulated using the product template in the ABC system for a standard batch size to give a cost per unit.
In France the product is blended, then sterilized, the standard cost of the blend at each processing stage includes the cost of raw material, interim packaging, labour cost and overhead costs. As the individual raw materials are combined into the blend by the production process, the costs are then tracked against a work in process (WIP) code.
|Transfer to France
The blend is transferred to France in large bags (400 kg), the transport is provided by a third-party logistics operator (3PL). The company has negotiated an average price per load with the haulier which allows calculating an average cost per bag.
This product is packaged in France, where a similar ABC approach is used in the packing activity, except the cost unit is a single jar compared to a case in the UK. The packaged product is priced in K per jar and a standard exchange rate is used to convert the cost into £ per case.
The sterilized blend and associated packaging costs, e.g. jar, cap, label etc, are combined at this stage to give the manufacturing cost of the product, line packaging overheads costs are distributed to the product using an activity-based approach as described earlier in the production process for GB-1. A standard change over allowance and a 3% standard loss for materials and packaging is included into the product cost calculation. The product cost is expressed as a cost per jar. The product is then palletized and transferred internally to the finished goods warehouse.
|Deliver||The delivery activity begins with the transportation of the finished product from France and concludes with the merchandiser placing a jar on the retailer’s shelf.
Transport to United Kingdom
The product is palletized and transported back to the UK by a 3PL at a standard price per load for an average of 45 pallets.
The product is received into a finished goods warehouse operated by a 3PL. A standard charge of per pallet received is made in addition to a fixed charge per month regardless of usage made for storage of finished goods.
Distribution to merchandiser
The 3PL provides three activities which have an agreed standard tariff i.e. picking an order, administering the picking order and delivery of the order to the merchandiser stock point.
Sales support costs that are associated with this stage are included and absorbed to product at an average cost per case.
The outbound logistic activity is shared with a 3PL forwarder, the finished product is stored and order processing, picking and consolidation are carried out in-house and then the product is delivered to a number of regional distribution centres (RDC) in France. The final leg to the retailer is undertaken by a 3PL forwarder who consolidates the products with other products destined for the store.
The finished goods warehouse is shared with a sister operation. The costs of the warehouse facility are recovered using a combination of allocation, apportionment and absorption to calculate an average cost for either € per kg delivered or € per pallet depending on the distribution channel to market.
Distribution to store
The finished product is received at the point of sale via the 3PL forwarder. Regional sales personnel are responsible for placing the product on the shelf.
The costing methodology used for product GB-1 combines standard costing for raw material inputs (including packaging) and activity-based costing (ABC) for the distribution of, sourcing and manufacturing activity costs (direct and indirect) of the products manufactured at their UK factory. This general approach has now been adopted by the French division for costing their products.
Both divisions have adopted different supply chain approaches to the distribution of their retail products, which means they require different costing approaches. Key characteristics and considerations of the costing approaches employed for both products include:
• The objective of the product costing system is to maximize the distribution of manufacturing overheads to the products that consume the activities, i.e. move costs from below the gross profit line to include them in the cost of goods sold calculation.
• There are multiple handling units for different supply chain activities and this makes it difficult to visualize the incremental cost of the finished product, unless a form of equivalent cost unit is applied to the supply chain.
Where possible, the budgeted costs for raw materials and in-house activities and the average rates for third party activities have been used to calculate the incremental product cost as it flows through the supply chain from receipt of raw materials to delivery at the point of sale. Where it was not possible to obtain a budget cost for an activity, assumptions were made. As there was no equivalent unit across the supply activities, a cost per case was used, as this is the common sales order unit.
• Inbound procurement and logistic costs are treated differently; in France, an average of these costs over volume received was estimated, while in the UK, these costs were included as indirect costs.
• Sales support costs for merchandisers in the UK were included in the delivery cost per case, while in France these costs are not recovered by product but are accounted as a central support activity.
The aim of this analysis was to follow the accounting culture/spirit of both organizations in terms of trying to trace the cost of activities consumed by products, so maximizing the cost of goods sold calculation and minimizing the amount of overheads that cannot be traced to a specific product or activity.
When all the costing information from the various sources throughout the supply chain processes is combined and the different handling units (pallets, kg, jars and cases) are converted into an equivalent unit, it becomes possible to visualize and calculate a supply chain cost for both products. Merchandising and packaging costs account for around 81.1% of the cost of GB-1, while the actual cost of the raw materials represents 8.1%. In the case of FR-1, packaging costs account for 61% of cost, the next largest component is the raw materials, which equates to 13%. Figures 12.7 and 12.8 illustrate the cumulative cost of a case as it flows through the supply chain process for each product.
For GB-1 there are two significant increases in cost when the product is packaged and when it passes through the merchandising network to the point of sale. For FR-1 there is only one significant increase during the packing process.
This section combines the time and cost analysis outlined in previous sections and explores the relationship between these variables for both GB-1 and FR-1 as they flow through their respective supply chains from sourcing to delivery at the point of sale. This cost–time profile can be used to chart the complete supply chain and provide an insight into the relationship between the cost and time of individual supply chain activity clusters and can be used to highlight areas which require further investigation. Figures 12.9 and 12.10 illustrate the cost–time profile for each product at specific points along their supply chain combining both cumulative time and cost.
Two interesting time–cost couplings are highlighted: warehousing and packaging. Warehousing, where the percentage of total case cost for both products is relatively small compared to the percentage of time, but when the time is broken down into value added, non-value adding time and inventory time this confirms the need to investigate these activities further. On the other hand, the packaging process for both products accounts for a relatively high proportion of the total cost, but only accounts for a tiny proportion of total supply chain time. In the case of GB-1, 51% of the total case cost is attributed to the merchandising process compared to only 14% of supply chain time (see Table 12.4); a further investigation into the costing method and types of costs that are allocated to this activity may be worthwhile.
The SCTCM framework does not take out time and cost in a supply chain, but it assists the process by presenting the current situation, identifying areas of opportunity and providing an important input to developing focused process improvement initiatives which are then targeted to reduce waste and cost in the supply chain. Table 12.5 highlights the outputs of the SCTCM framework which illustrates the area opportunities for both the French and UK supply chain operations.
The supply chain time and cost mapping framework provides organizations in a supply chain with enhanced visibility of both time and cost along the processes. A major finding that became apparent during the development of the framework was that the relationship between cost and time in processes is non-linear. This challenges the traditional view that reducing nonvalue adding time implies a proportional reduction in cost. The case studies that were used to develop the framework indicated that over 82% of supply chain time may be classified as non-value adding.
Feedback from industrial partners involved in the development of the framework was extremely positive. The approach enabled these organizations to implement ‘in-house’ projects to evaluate waste and its associated costs, which resulted in the introduction of various quantifiable process improvements. The outputs from these company-based projects increased the awareness of their people with regard to current supply chain issues and importantly the impact of cause and effect relationships in the process, especially when making decisions that have an impact on the wider supply chain.
The project teams consisted of people from different functions and a benefit which was not anticipated was the improvement of relationships between financial and operational personnel. This was important as during the development of the framework it became apparent that financial information was not usually shared between supply chain partners. The framework gave the organizations a structure and a set of tools for supply chain analysis and design which improved their ability to analyse the total cost of a product by activity and increased visibility of cost and time in their processes.
The authors would like to acknowledge the support and guidance given to them by all the members of the Supply Chain Costs and Effective Swift Service (SUCCESS) Steering Group especially Linda Whicker and Mike Bernon. The steering group comprises representatives from our industrial partners, The Chartered Institute of Logistics and Transport (UK), Warwick Manufacturing Group, at Warwick University and Cranfield Centre for Logistics and Supply Chain Management at Cranfield University. The SUCCESS research project was jointly funded by the Engineering Physical Science Research Council (EPSRC) and industrial partners.