The cost of complexity

It can be argued that an increasing proportion of total end-to-end costs in the supply chain are driven by complexity in one form or another. Often these costs may not be readily transparent as they are hidden in general overheads or the costs of carrying inventory, which as we observed in Chapter 3 are not always properly accounted for. 

Underlying much of the cost of complexity in the supply chain is the Pareto Law (the so-called 80 20 rule). Vilfredo Pareto (1848-1923) was an Italian industrialist, sociologist, economist and philosopher. In 1909 he identified that 80 per cent of the total wealth of Italy was held by just 20 per cent of the population. Thus was born the 80 20 rule that has been found to hold across many aspects of social and economic life. In Chapter 2 it was suggested that an 80 20 relationship exists with regard to customers and products, i.e. typically 80 per cent of the profit derives from 20 per cent of the customer and likewise 80 per cent of the profit comes from just 20 per cent of the products. Generally this 80 20 relationship applies across most elements of the supply chain and is a key contributor to complexity and hence cost. 

Most businesses will find if they perform an 80 20 analysis that they have a long-tail of customers who, whilst significant in numbers, actually contribute very 

However, for most companies it is likely that a selective rationalisation of slow-moving lines will have a positive impact on overall profitability. 

---

One of the challenges in designing a wideband MIMO system is tremendous processing requirements at the receiver. MIMO symbol detection involves detecting symbol from a complex signal at the receiver. This detection process is considerably complex as compared to single antenna system. Several MIMO detection techniques have been proposed [8], These detection techniques can be broadly divided into linear and non-linear detection methods. Linear methods offer low complexity with degraded BER performance as compared to non-linear methods. This paper focuses on non-linear detectors and makes an effort to improve BER performance at the cost of complexity and vice versa. ML and V-BLAST detectors [9],[10] are well known non-linear MIMO detection methods. ML outperforms VBLAST in BER performance, while VBLAST is lesser complex than ML. In [11],[12] a performance complexity trade off between the two methods have been reported. 

A 3x3 (NtxNr), 4x4, and 4-QAM 6x6 MIMO system is simulated. The symbols x,-and number of algorithm iterations (Nur) depends upon N, and QAM constellation size. For 3x3, 4-QAM system, x, equals 6 and it grows to 12 for 6x6,4-QAM system. Nitr is kept in the range of 10 to 20 in our simulations. Iterations are according to the system requirements. Larger Nur can result in better BER at the cost of complexity. However, the algorithm reaches saturation after a certain number of iterations and therefore Nur needs to be tuned carefully. Optimum value is taken after a number or trials to find the best BER with least complexity. 

Lowering the cost of complexity avoiding overly expensive agility... 

Many organisations face challenges related to the risk of driving responsiveness over the top in the wrong areas of focus. Three examples illustrate the cost of complexity ... 

The procedure for determining the cetane number in the CFR engine is not extremely widespread because of its complexity and the cost of carrying it out. There also exist several methods to estimate the cetane number of diesel fuels starting from their physical characteristics or their chemical structure. 

The complexity of the force computation function described here is computed by counting the number of force terms evaluated by each processor. The cost of force computation for processor i, which is denoted by C is,... 

Time, Cost, and Equipment Analysis time can vary from several minutes for samples containing only a few constituents to more than an hour for more complex samples. Preliminary sample preparation may substantially increase the analysis time. Instrumentation for gas chromatography ranges in price from inexpensive (a few thousand dollars) to expensive (more than 50,000). The more expensive models are equipped for capillary columns and include a variety of injection options and more sophisticated detectors, such as a mass spectrometer. Packed columns typically cost 50- 200, and the cost of a capillary column is typically 200- 1000. 

The total number of integrals computed depends greatiy on the level of complexity of the method time cost savings of 2 orders of magnitude can be realk ab initio theory n vs n ). 

Because of the high costs of raw materials and the relatively complex synthesis, the 2-cyanoacryhc esters are moderately expensive materials when considered in bulk quantities. Depending on the quantity and the specific ester or formulation involved, the prices for cyanoacryhc ester adhesives can range from approximately 30/kg to over 1000/kg. For these reasons, as weU as several technical factors related to handling and performance, cyanoacryhc ester adhesives are best suited to small bonding apphcations, very often where single drops or small beads are adequate for bonding. In such cases the cost of the adhesive becomes inconsequential compared to the value of the service it performs, and these adhesives become very economical to use. 

Budgeting. These changes in the storage and retrieval of chemical information requite that Hbraries and information centers now consider not only what should be purchased but also what monies should be allocated for the purchase of information in nonprint formats such as CD-ROMs (compact disk read-only memory) and on-line databases. Coupled with this is budgeting for the cost of hardware and software to enable the rapid and cost-effective deHvery of needed information (15). The geometric increase in sources, both printed and on-line, has increased the role of information speciaHst as an expert in the deHvery of chemical information. Retrieval from increasingly diverse and complex sources becomes the paramount issue for searchers of chemical Hterature in the 1990s. 

Manufacturing engineers wishing to use ECM processes in industry need to address the challenge of proper tool design. The cost of design can be as much as 20% of the cost of an electrochemical machine for complex components. PredictabiUty of overcuts obtained for specific appHcations and the particular electrolytes to be used for the alloy metals that have to be machined must also be considered along with specific controls and limits on the ECM equipment needed. 

Costs. Since much more personal contact work is requked, the cost of marketing research studies is significantly higher than the cost of market research studies. Also, the advisabiHty of using the most senior personnel raises the cost. It is not uncommon for in-depth marketing research studies to cost 35,000 to 100,000, depending on the complexity of the subject. 

Immobilization. The abiUty of cyclodextrins to form inclusion complexes selectively with a wide variety of guest molecules or ions is well known (1,2) (see INCLUSION COMPOUNDS). Cyclodextrins immobilized on appropriate supports are used in high performance Hquid chromatography (hplc) to separate optical isomers. Immobilization of cyclodextrin on a soHd support offers several advantages over use as a mobile-phase modifier. For example, as a mobile-phase additive, P-cyclodextrin has a relatively low solubiUty. The cost of y- or a-cyclodextrin is high. Furthermore, when employed in thin-layer chromatography (tic) and hplc, cyclodextrin mobile phases usually produce relatively poor efficiencies. 

The crown ethers and cryptates are able to complex the alkaU metals very strongly (38). AppHcations of these agents depend on the appreciable solubihty of the chelates in a wide range of solvents and the increase in activity of the co-anion in nonaqueous systems. For example, potassium hydroxide or permanganate can be solubiHzed in benzene [71 -43-2] hy dicyclohexano-[18]-crown-6 [16069-36-6]. In nonpolar solvents the anions are neither extensively solvated nor strongly paired with the complexed cation, and they behave as naked or bare anions with enhanced activity. Small amounts of the macrocycHc compounds can serve as phase-transfer agents, and they may be more effective than tetrabutylammonium ion for the purpose. The cost of these macrocycHc agents limits industrial use. 

---